Here is my experience with the ppa update. I hope it helps.
I have applied the focal ppa package 2:4.15.13+dfsg-0ubuntu0.20.04.4~ppa1 over the latest official security update (2:4.15.13+dfsg-0ubuntu0.20.04.3) and the bug that was originated with the KB5028166 windows update has been successfully resolved.
No reboot has been necessary, nor on the client, nor on the server side.
The response of the "Test-ComputerSecureChannel" command is satisfactory as it returns "True" after applying the ppa package. Other bugs with GPO directives that failed with the trust relationship have also been fixed.
Here is my experience with the ppa update. I hope it helps.
I have applied the focal ppa package 2:4.15. 13+dfsg- 0ubuntu0. 20.04.4~ ppa1 over the latest official security update (2:4.15. 13+dfsg- 0ubuntu0. 20.04.3) and the bug that was originated with the KB5028166 windows update has been successfully resolved.
No reboot has been necessary, nor on the client, nor on the server side.
The response of the "Test-ComputerS ecureChannel" command is satisfactory as it returns "True" after applying the ppa package. Other bugs with GPO directives that failed with the trust relationship have also been fixed.
I do not see any additional malfunctions.