Don't even worry about it. It happens to me a lot of the times and I feel like I have to change my settings just so I can get back that consistency.
Playing more is a good suggestion, but don't take it the wrong way...thinking that it'll negatively affect your progression. Download new set of maps, play them, switch it up, and try your fav maps again. You'll see that improvement over time
It seems to me that your brain adjusts to what you play.
Say I want to play an average, kinda jump-ish 5* map. If preceded by a 6* fun session, I'll likely be accurate. If preceded by a 3* mp session, I will most likely still be in slowpoke mode and process the patterns too slowly to fully control what I'm doing.
My answer would be, avoid getting bored by always going through the same maps as a warmup, enjoy the excitement of playing new maps or maps that are just a tiny bit out of your reach, and then go back to whatever you were trying to FC (not more than 3-4 attempts per map per session to avoid turning into a salt dispenser). Worked for me, might work for you. Most importantly, have fun !