Thank you! Now I understand.
I took another step to resolve the issue — I restored a backup of my database, then proceeded with the database update again. This time, I finally saw green box (both in Chrome and in Firefox, because I wanted to try all of this twice, in both browsers):
The installer has finished successfully
Take me to the ACP
The database update was successful.
The installer has finished successfully…
100%
100%
In the admin log, I found the same message as yesterday:
Anonymous 04 Nov 2024, 13:46 Updated Database from version 3.3.0 to version 3.3.13
It seems yesterday's update was actually successful, but now I'm sure about it
Thanks so much for all your help!