New comments disappearing in my studies

Just had one of the bugs happen. Annotating a game. Put a longish (17 lines) comment before the first move. REC button was green. Clicked it twice. Now green. Edited the comment to have one more line. Clicked REC twice. Now the line I just added is in the move window (Inline notation is on) but missing from in the comment window below the board!

Refreshed the page. Removed the new line. Hit REC twice. Put the new line in again Hit REC twice. Now the new line shows up in the comment window below the board and not in the move window! Several attempts to delete that line, hit REC twice, and the line will not stay deleted. And the new line still does not appear in the move window.

So delete the line, clicked REC *once*, it turns red, refreshed the page with F5, and the REC button is now green and the new line of text is gone from both windows.

Added the new line, clicked REC once, refreshed the page with F5, and the REC button is now green and the new line of text is in both windows.

Windnows 10 64-bit
Firefox 85.0.2 (64-bit)

I could not reproduce this in Edge!
Edge
Version 88.0.705.74 (Official build) (64-bit)

By "new line" above, I meant a line of text; not the NL character. :-)

Could not reproduce the bug for a long time. New comments were saved.

However, today one part that I reported happened again and this time I have a screenshot:
ibb.co/bXMXjtT

When I edited this comment, the number of the comment icon is incremented and when I go back and fourth to the position, the comment stays in the unedited state.

When you let the analysis run for a long time, it sometimes "times out", meaning it will jump to the chess starting position. Maybe this is a key part to reproduce this kind of bug.

Some comments from yesterday have disappeared over night, including the position I was showing in my last post. Here's how I found the position today morning: ibb.co/WWc81wj

I had not done anything to the study in the meantime. This bug may have corrupted the study or something.

I was again browsing in my study and found a lot of positions, where my comments got deleted.
Conspiciously, those were all positions where it was whites turn to move.

Here are some of the positions where my comments got deleted:
ibb.co/8MyXNzW
ibb.co/RQdFy31
ibb.co/ncjMj0J

Additional information: I'm using Google Chrome.
Not sure if any of this helps. Thanks for trying to reproduce the bug. I must be doing something differently than other people, since not many seem to have this problem.

I tested if changes are saved if I again write a comment where the comment was deleted. Here's what I wrote yesterday:
ibb.co/sFrpGLH

Today there is no comment for this position (no transposition):
ibb.co/5vXmKwL

It seems once the bug has occurred, comments for certain positions are not permanently saved.
(Temporarely they are saved but I don't long how long it took for the comment to disappear.)

lichess.org/study/4YxFzULK can you take a look at this one please @thibault I have added notes in the comments on the study so you can see what is happening. Thanks