You report bugs on Answer HQ, like Sims 4 Answer HQ for The Sims 4. Sign in with your EA account and then you go to the right category. Normal bugs are reported in the Bug Reports category.
You can also search there for existing bug reports as the chance is pretty high that someone have reported the bug already.
Comments
You can also search there for existing bug reports as the chance is pretty high that someone have reported the bug already.