I think what Checo has been struggling with are the recent changes by Newey to the design of the RB19; I think with Max's wanting a very "pointy front end" of the car, where he can "drive it on the nose", is not what Checo wants, which is a truly "neutral-steering" car.
From an article in The Athletic: What sets Verstappen apart is his ability to deal with a very loose rear end, to feel when the rear of the car is at the limit before bringing it under control. That allows him the extra “pointy” front end that lets him chuck into corners faster and harder than his opponents, getting the most out of a Red Bull car that is already the class of the field.
Quote from Checo:
“We both want a good front end. It’s just a question of how stable the rear end can be,” teammate Pérez explained in Bahrain last week when asked about Verstappen’s driving style. “Max has been able to cope with a looser rear end.”
This is Checo's public explanation , for his poor performances, I don t buy it and no one with any racing knowledge would, not at this level. It's a known known e setups will always be favored differently from driver to driver, max nor checo chooses the setups , sims and track data engineers do, the driver adjusting to the data excels , notice , "adjusting " , so less say checo cant drive the suggested setup even after reviewing Max's data , this will never account for him being that much slower , not 7 places slower , not multiple dnf's , not falling off and colliding into others and surely not being able to race to a competent place when his teammate is 12-18 seconds in the lead ,etc ...
Checo also has the ability to make the changes to make him more comfortable , slower perhaps over a lap , but much better race performances over a full GP, so ,
1. Checo is really driving over his head trying to catch Max or
2. the team is sand bagging him ,
Regardless Checo is obviously not on Max's level , there's also a big personal Issue between the two, so i"m leaning towards no1 with a mix of no2 thrown in , Checo will be out at RB IMO, with the justification being his poor performances ...
The replacement will be interesting .....
Regards