If your Mac has been struggling with bugs and/or performance issues on macOS Big Sur 11.5 or an older version of macOS, you should think about giving macOS Big Sur 11.5.1 a shot.
Apple didn't call out any bug fixes in the macOS Big Sur 11.5.1 update's change log, but new versions of macOS have been known to fix unlisted issues. The macOS Big Sur 11.5.1 update could fix performance issues like severe battery drain, busted Wi-Fi connectivity, UI lag, Bluetooth problems, random reboots, lockups and freezes, and various issues with first-party applications.
If you missed macOS Big Sur 11.5 update, it had two bug fixes on board:
- Fixed an issue where Music may not update play count and last played date in your library.
- Fixed an issue where smart cards may not work when logging into Mac computers with the M1 chip.
If you've been dealing with one of these problems, and you missed macOS Big Sur 11.5, you'll want to install the latest version in the near future.
If you missed macOS Big Sur 11.4, you'll get its fixes. It had five bug fixes on board:
- Fix for an issue where Bookmarks in Safari may get reordered or moved into a folder that can appear hidden
- Fix for an issue where certain websites may not display correctly after your Mac wakes from sleep
- Fix for an issue where keywords may not be included when exporting a photo from the Photos app
- Fix for an issue where Preview may become unresponsive when searching PDF documents
- Fix for an issue where 16-inch MacBook may become unresponsive when playing Civilization VI
If you skipped macOS Big Sur 11.3, it had a number of bug fixes on board. Here's the full list:
- Fixed an issue where Reminders created via Siri may be unintentionally set for early morning hours.
- Fixed an issue where iCloud Keychain might not turn off.
- AirPods audio routing to incorrect device for Automatic Switching
- Fixed an issue where AirPods Automatic Switching notifications might be missing or duplicated.
- Fixed an issue where External 4K monitors may not display in full resolution when connected over USB-C.
- Fixed an issue where the Login window may not display properly after restarting Mac mini (M1, 2020).
- Fixed an issue where the Dwell feature may not work in the Accessibility Keyboard.
If you missed macOS Big Sur 11.2.3 and macOS Big Sur 11.2.2, you'll get additional bug fixes with your upgrade.
macOS Big Sur 11.2.2 prevented MacBook Pro (2019 or later) and MacBook Air (2020 or later) models from incurring damage when connected to certain third-party, non-compliant powered USB-C hubs and docks.
If you missed macOS Big Sur 11.2.1, you'll get its fixes when you upgrade. macOS Big Sur 11.2.1 addressed an issue that could prevent the battery from charging in some 2016 and 2017 MacBook Pro models. A newer macOS Big Sur 11.2.1 build also fixed a very serious installation issue where not having enough free space available for a macOS Big Sur update could lead to potential data loss.
If you missed Apple's macOS Big Sur 11.2 update, you get its bug fixes with your upgrade. macOS Big Sur 11.2 included the following fixes:
- Addressed an issue where external displays may show a black screen when connected to a Mac mini (M1, 2020) using an HDMI to DVI converter.
- Addressed an issue where edits to Apple ProRAW photos in the Photos app may not save.
- Addressed an issue where iCloud Drive could turn off after disabling the iCloud Drive Desktop & Documents Folders option.
- Addressed an issue where System Preferences may not unlock when entering your administrator password.
- Addressed an issue where globe key may not display the Emoji & Symbols pane when pressed.
If you skipped macOS Big Sur 11.1's, you get its bug fixes too. Here's what was on board Apple's macOS Big Sur 11.1 update:
- Addressed an issue where QuickTime Player might quit when opening a movie with a timecode track after upgrading from macOS Catalina.
- Addressed an issue where Bluetooth connection status was not displayed in Control Center.
- Improved the reliability of unlocking your Mac automatically with your Apple Watch.
- Addressed an issue where the trackpad scrolling speed may be faster than expected on MacBook Pro models.
- Addressed an issue where LG's UltraFine 5K Display may incorrectly display at 4K resolution on Macs with M1.
If you can't seem to find a fix for your issues, you should consider moving up to the latest version of macOS Big Sur. It could help. | 
Cindy
01/26/2021 at 8:08 am
Big Sur is terrible. My computer runs so much slower I’m ready to throw it out the window. Don’t download this program.
Bob Gardner
01/26/2021 at 9:28 am
cannot maintain connectivity of screen share. One or both of us lose screen control. constant disconnects and frequent reboots. covid forced at-home business is getting impossible with Big Sur.
I have a brand new 2019 MacBook Pro and my partner has a fairly new 2016 MacBook Pro. We were doing just fine on Catalina then switched to Big Sur and everything went to hell…we gave it a week to settle in with all of its syncing and updating stuff but then found that performance issues and bugs like entire system shut downs and black screen and spinning wheels started happening… this is supposed to be the best hardware we can buy and yet hampered by Big Sur and its issues is causing us to rethink going back to Catalina.
Trevor Martin
02/28/2021 at 2:32 am
I have a MacBook Pro 2016. Big Sur automatically updated and as a result I can no longer use the MBP as a clam when connected to my BenQ 2700 monitor that I need for photo editing. When I try to log into my MBP in clam mode the screen goes blank after about 10 seconds and says it is not receiving a signal. Seriously! This latest update was supposed to sort a few things out for 2019/20 MBP …. not f**k a 2016 model… Unbelievable. Thanks Apple..
Richard Welliver
03/03/2021 at 7:40 pm
Big Sur update 11.2.1 and now 11.2.2 will not update on my iMac (Retina 4K, 21.5-inch, 2019) It seems to download but when installing i get a error message that there is a problem with my internet connection.
Michelle
03/10/2021 at 2:01 am
I have updated my MacBook Air late 2020 to 11.2.3.
Can’t really see any difference. Since I bought the
new MacBook the only problem I’ve had (which is very
annoying) is that the auto login option is greyed out
and I cannot disable the automatic login. In Library/
Preferences the com.apple.autologin etc. is missing.
Surprisingly enough I installed MacOs Catalina on my
old MacBook Air mid 2012 and it works perfectly.
Puran
05/11/2021 at 6:45 am
Actually i have a macbook air 2017 whose battery was not charging when i was using Catalina OS after updating it to the Big Sur the battery is charging now and is giving around 3 hours of battery backup. Will change my battery with in 10-15 days. Updating macOS worked well for me.
Paul
05/24/2021 at 3:21 pm
Same here.
After installing the 11.2, I had my laptop running crazy and my battery, which still held 9-10 hrs, got depleted to roughly 4 hrs….
L. Mayhew
06/01/2021 at 8:43 am
I upgraded form macOS Catalina 10.15.7 to Big Sur……..Big mistake……..slow, balky, and unreliable. Mac support walked me through reinstalling Catalina..Thank you support!
Linda
06/29/2021 at 11:53 pm
2017 Macbook Pro – updated Big Sur about three months ago and Touch Bar stopped working when restarted. Updated to 11.4 hoping would fix and now camera is black and doesn’t show content (system says it is there but nothing). Have tried so many things but nothing but frustration.