Tucked buttoned shirts become 'untucked' when adding too many layer details

Yes, this is a known issue that happens with too many skin details.

Thanks for your reply ! It's nice to know why this is happening.
Do you know if this issue is planned to be corrected ?

I don't work for EA so unfortunately I don't have that kind of info. Since there aren't that many me toos on the original AHQ thread (linked in your post), I would post there as well and make sure to me too.

I have the same problem and it’s very annoying. 

Had this issue with a Sim who had body hair, tattoos, skin details and scars. After becoming a Werewolf, I decided to add one more scar, but it was one too many — not only his buttoned shirts got untucked, but I think some other Sims’ as well! (Or maybe it was a recency bias on my part?)

After removing one skin detail the issue disappeared on my Werewolf. 

Given the new tattoo system in Hobbies & Businesses seems to use more layering, this issue could become really prevalent in the coming weeks.