Hello,
If you are unable to find the Cumulative Update for Windows Server 2019 (KB5028168) in the list of installed updates when attempting to uninstall it, you can try the following steps to reverse the update:
Use Command Prompt:
a. Open Command Prompt with administrative privileges.
b. Type the following command and press Enter:
wusa /uninstall /kb:5028168
Use DISM Tool:
a. Open Command Prompt with administrative privileges.
b. Type the following command and press Enter:
dism /online /get-packages | find "5028168"
c. Note the Package Identity of the update.
d. Type the following command and press Enter (replace Package Identity with the actual value):
dism /online /remove-package /packagename:PackageIdentity
Best Regards