Created attachment 186676 [details]
Test file demonstrating animation problems when returning from previous slide

When in presentation mode, animated items such as bulleted text do not display in the correct order when the user returns to a previous slide.

Expected behavior: when returning to a previous slide by pressing backspace or left arrow, the previous slide should appear in its "final" state, with all animations having completed.  In my case, that means that all bulleted items should appear. In the attached sample file, the only animations are bulleted text items that should enter individually one at a time, one per click. 

Current behavior: when returning to a previous slide by pressing backspace or left arrow, some animated items appear but some do not. When I proceed to press backspace again, animated items do not disappear in order and some items.

Please see the attached file as an example.

I know that this sounds like a duplication of another bug (#137454), but that other bug is listed as solved yet the problem persists in 7.4.6.2.

To reproduce:

1. Open attached test file. 
2. Navigate to third (last) slide.
3. Enter presentation mode with this slide (shift-F5)
4. Press backspace. The previous slide appears, but the top bullet does not display.
5. Press backspace again. Two bullets disappear. Only the bottom bullet should disappear.
5. Press backspace again. All bullets disappear. At this point, only two bullets were visible, so the third (bottom visible) should disappear, leaving the second visible.  The first bullet is never visible, but of course it should be.

This behavior happens on most of my Impress files. As a teacher who often needs to return to previous slides, I experience this bug daily.

(Thanks to devs for their hard work!)

My system: LO 7.6.4.2, Ubuntu Linux 22.10