Steps to reproduce the issue

Issue reproduce BEFORE installing a new nightly build.

Create any override for Atum or Cassiopeia template. Remember which override you created (for example, com_content - article).

Download the new nightly build, make any changes to the layout of what you just created the override for (for example, add the tags div, br, p, etc, or temporarily remove some line).

Install nightly build. After installation, you will immediately receive a message that "n files" have been changed. Go to System - Templates (Site) - Cassiopeia, note that the last column contains the same information - "n changes".

Once I click on the Cassiopeia options (in this case), under the Updated Files tab, everything is fine. I can't get the list of files with changes in any way.

Everything was tested on RC2 + updates from nightly builds (a lot - updated every day).