3 weeks into options trading, got early assigned on puts

Heard a lot in the learning phase that early assignment is super rare. Did I just get really unlucky?

I had a put spread that now has half of it left unassigned. Brokerage shows the shares in my portfolio. I was 3 days from expiry on these PLTR 75 puts.

Just curious as to how often this should be expected based on other experiences out there?