i'm using Opera Developer 98 with these extensions:
Microsoft Edge stable has the same extensions, but doesn't have the issue.
While part of the Adguard window is blank, those functions in the window don't work.
Sometimes the issue can be resolved by reloading and/or closing and reopening the websites.
Example websites are Adguard, Adguard forums, Opera blogs, Opera forums.
@N0Ad$ I couldn't reproduce this problem on my side. Can you please reinstall AdGuard extension? If this doesn't work, reinstall the Opera Developer and try reproduce the problem again. You can write results here.