I updated some T4-based sites and one T3-based site (Ja Mason) to J6.
The same problem occurs on all of them.

If I select a file as shown in the photo, the Check Overrides button remains disabled. Note that normally, when I select one or more files, the button changes from gray to active. Even when, as in the attached image, the files are already green-checked (the same button is also used for Uncheck).
You can still check by clicking the files one at a time. But what I described isn't the normal behavior; something is wrong.
For example, if I wanted to uncheck a file, I couldn't.
I repeat, the problem occurs with J6 and templates based on both T4 and T3. Everything works fine with the same sites in version J5.
Could you verify that the bug I described exists?
Thanks in advance.
Francus