Is this sleep regression?

JC

My 4 month old boy used to go down for bed between 630/7pm no problem. Bedtime routine and in bed without any fussy. For the last week+ now, he will cry/fuss until 8/9pm every single night. Once he’s down, he will sleep until morning but it’s been a battle putting him to bed. I am hoping this will pass but I feel so bad because he is fighting his bedtime soooo bad.