If you pay on your due date, that's not quite the statement date. My Flex that statemented 4/8 is due 5/5.
Can you look at your bill payments in Jan, Feb, March 2020 and confirm which payment is the one that you broke $4k in payments to chase for that card number? If it was the Mar 2020 payment, those points hit in February. If it was the February payment, those points hit in January, etc.
Or, think of it this way. You opened 11/2 and had 90 days to hit spend, so you hit the spend no later than 2/2. That card then likely statement some time in Feburary, early March at the very latest, so you're over 4 years since you earned that bonus.