Skill going up way too fast

I saw some older posts about this but there was no solution provided.

My sim's skills go up immediately. She starts rock climbing, the next second it's already level 2, then few seconds later level 3, etc. Same for all other skills too. It takes 2 real-life seconds for her skills to level up.

She has no base traits that should do this (competitive, goofball, socially awkard, adventurous, perfectionist), she has a lot of reward traits but only the same ones as she had before, and this issue has not occured before. With the only exception being Wordly Knowledge from the Mount Komorebi sightseer aspiration, but that shouldn't have such an effect. She has a couple childhood reward traits that can boost skills but she always had them and the skills always levelled up at a normal pace.

So, she has only the same traits as when there was no such issue (except for that one above), and nothing should result in the skills shooting up a level in a couple seconds.

No lot traits either, and no mastery perks that should do this (she has the one that helps others build physical skills faster when activated, but that shouldn't result in this for her own self and is not even activated).

She wasn't in a focused/inspired etc. mood. It wasn't "new skill day".

So it really doesn't seem to be a boost (and even a boost shouldn't result in immediate leveling), but a bug.

Never used any mods or CC at all.

Playing on PC.

Thank you!