This morning Magisk notified me about the update available (from 23.0 to 24.1). To cut the long story short, it was a complete failure and I was able to revert back to 23.0.
First upgrade went unsuccessful. Magisk stopped loading. Root was lost. Yet it has succeeded to write something into boot, so uninstalling app and reinstalling 23.0 didn't help. Reboot into patched BL didn't give 23.0 root permissions to patch the BL. I have succeeded to patch stock BL with 24.1 and boot into that, then install 24.1. This has root but fails safety net. Now you need to manually flash safetynet-fix-v2.2.0.zip because Magisk does not do magisk hide anymore. That is lost and module library is lost, plus safety net check tool is lost too. OK, with the fix it can pass the basic check, but for example Citi mobile app sees the root anyway. I have decided to downgrade to 23.0 because I only see a loss in functionality without any benefits.
Now you cannot patch BL with 23.0 if you have 24.1 there. You cannot do it if you flash stock BL but have traces of 24.1 app. The only thing which worked for me: in the functional 24.1 app select 'uninstall magisk', 'complete uninstall', then do root from start: install app 23.0, boot into patched with 23.0 BL, direct install from the app. Half a day is lost.
To prevent it from offering any further upgrade I went into app settings, selected custom update channel and pasted there a link to the 23.0 manifest from github. So long as the project is there that shall work.
Bottom line: beware magisk above 23.0!
First upgrade went unsuccessful. Magisk stopped loading. Root was lost. Yet it has succeeded to write something into boot, so uninstalling app and reinstalling 23.0 didn't help. Reboot into patched BL didn't give 23.0 root permissions to patch the BL. I have succeeded to patch stock BL with 24.1 and boot into that, then install 24.1. This has root but fails safety net. Now you need to manually flash safetynet-fix-v2.2.0.zip because Magisk does not do magisk hide anymore. That is lost and module library is lost, plus safety net check tool is lost too. OK, with the fix it can pass the basic check, but for example Citi mobile app sees the root anyway. I have decided to downgrade to 23.0 because I only see a loss in functionality without any benefits.
Now you cannot patch BL with 23.0 if you have 24.1 there. You cannot do it if you flash stock BL but have traces of 24.1 app. The only thing which worked for me: in the functional 24.1 app select 'uninstall magisk', 'complete uninstall', then do root from start: install app 23.0, boot into patched with 23.0 BL, direct install from the app. Half a day is lost.
To prevent it from offering any further upgrade I went into app settings, selected custom update channel and pasted there a link to the 23.0 manifest from github. So long as the project is there that shall work.
Bottom line: beware magisk above 23.0!