Depends on what you mean. I would have to go back & check but there were a couple throughout the show’s run.
When Carla & Turk got married.
When JD became on the same level as Cox.
When he grew that beard.
After Kelso retired.
The Janitor getting a girl.
Getting Kim pregnant.
Etc.
earlier in season 5, it sorta, just SORTA started to seem a little over the top with the goofiness, more so by JD.
then him instantly hooking up with Mandy Moore and getting a house like seconds after they met
it turns back around a bit later in season 5, but it sorta just felt like they were jumping the shark a bit with the humor a bit at times
still good tho.
to tell you the truth, i think this is the first time i've watched every episode to episode from each season. because in real time, i had only watched random episodes from different seasons but didn't know know every detail about the show beforehand.