Whole new personality overnight for my 21month old

So my son is a real sweetheart, very easy and such a pleasure. On Friday he really struggled to go down for his nap, and since then, every nap and bedtime is a complete disaster 😩 He also seems to have developed a bit of a temper when he doesn’t get to do what he wants to do.

Along with this though, he has definitely developed loads in terms of speech, saying a few 2 and 3 word sentences, saying lots of new words. Seems as though he has gone through some kind of major developmental leap.

Anyone else experience something similar at this age?