I have the notorious glitch/problem, that my sims interrupt tasks in order to do other tings.
The 2 most notorious things:
1. I send them to shower/bath, they will get out of their clothes, get into the tub/shower and immediately get out in order to marvel at our talking Bop toilet
2. They eat a full plate of something and suddenly (even if their hunger bar still is red/yellow) will decide that eating is boring and they want to play a cards game at the gaming table instead (this usually happens when 2 sims are active in the same room ... seems like the engine then decides that these 2 sims automatically playing a cards game is more important than any other task the sims are doing)

Especially the second one is annoying, as deleting the gaming task (and reordering them to eat again) often is insufficient, as it happens all too often that their eating gets interrupted by the desire to play cards again

I should add that my game has all expansion packs (including seasons), various stuff and gameplay packs and no mods