Huge decrease in number of views from FYP

Hi. My gf’s tiktok account started to behave strange way recently. Number of views dropped significantly (from 30-60 k regularly, over 100k accidentally to below 10k) and they come from observers mainly (her FYP % was above 70%, now its below 5%), there are almost no new observers, likes do not grow as before. It happened almost overnight.
People (observers mainly) can see her in FYP, but say it’s not as frequent as it used to be.
Contents wise, she had one or two movies (out of 90), which raised discussion, but it was some time ago (no change in views, likes etc at that time) and they do not seem to be “worse” than some others.
Any ideas on what happened and how to “reverse” it?
If it is kind of content related ban (I doubt, but…), how to get rid of that? If deleting movies may help, how to learn which movie(s) was a troublemaker?
Deleting and re-creating account is not an option, as she cannot even think about loosing her few-month work…

I really count on your help
Take care,

did she change her content? or tried to post something different? is she posting everyday or stopped for a few days or weeks?

She used to post daily, or sometimes twice a day every second day.
When she realized what’s going on, she switched (hopefully temporarily) to posting once a week or so to check if it comes back

Just realized I have not answered all questions. Contents change - yes, she posted three or four clips with the dialogues in the background; before it was only music/dancing. I believe this is change “for the better” from tt perspective - dance can always be perceived as erotic, especially when the girl is attractive, dialogue, tested many times before, rather not.

Yeah i see, so what i can tell you is to get back to posting daily and get back to the same exact content that she was posting previously, maybe the followers did not like that change hence less engagement then TikTok decided to not push the videos the same way they used to, so she should try that and see.

Thanks a lot for the hint.
I wish it were that simple. Followers are even more active than before (comments\likes vs views % is much higher than before).
The real issue is low and dropping number of views coming from FYP. And this must be tt’s decision or algorithm. Looks like kind of a ban.

Any ideas on how to reach to them? Standard inquiry was disregarded…
If this was because of any particular post, any idea about how to find it?

As content of dominant post type has not changed recently (pretty girl dancing and teasing a bit or a bit more, like many others do), only idea that came to my mind is copyrights issue.
Any way to check if any of background music or dialogues did not violate the copyright law?