Post

Better on nighty, the position of the tooltip is good but not the tail. I am defining a margin-top on the element that should flip when the position change using flip-block (this part works fine). Then a pseudo element in inheriting that margin (this part is not working fine).

Perfect! As for the behavior, It's for sure related to the use of "unsafe center". Firefox is enforcing the unsafe behavior by having an overflow while Chrome is flipping to avoid the overflow. btw, the v147 of Firefox is having the same behavior as Chrome.