Weird things happens when i do crit builds on some champions

It has been a long time thing when i had this problem. When i tried to do crit builds on Ekko , i had a statikk shiv and 100% crit, and when i tried to use my e to jump on someone, ekko stops moving but still proc the shiv effect on target and the lightning never crits, you have to click twice on the same target to get ekko to jump to them. Another problem is that when i played mordekaiser i build a statikk shiv again and this time when i used his q to attack someone when shiv was full charged it stops his q animation and proc the shiv again it never crits, and then i saw that mordekaiser can crit with his q so the shiv should also be able to crit and yet it never happens. Can you guys please tell me if this is intentional or not because sometimes i just want to try crit builds on some champion that may not build that way.