I started to work with UC prof Version 18.104.22.1687 and had a similar problem:
I have opened 4 sessions, and in one session I changed a line and stored the change. UC should open the changed file automatically, but I always see the old file with no change, also when I tried to manually open the changed file.
In another session I was working with the same, now changed file, and in this session I could see the changed file.
Also in UE I could see the changed file, but no way to see the changed file in the session I was working first.
I must close UC, open it again and then I could see the changed file in all sessions.
Later, when I made other changes, UC worked correct, I could see changes in the active session, perhaps the bug is only when you have installed UC new and made the first change, I dont know.
I work many years with UE, it is a very fine tool; but after first tries with UC I am not very satisfied with this tool, there seem to be some other bugs and handling could be better.