Originally Posted by deepblonde

Corvette is right.
Even though the valve is the problem; it’s more than that -
It’s the design of the variable displacement compressor that leads to this issue, that pressure must increase ( by you increasing rpm’s to 3000) ; that even if you replace the valve with a brand new one , the issue may still be there - due to wear surrounding the valve or other unknown issues ;

That’s why it’d make sense to replace compressor with a conventional type , rather than another variable displacement, because even a brand new one problem may still be there , or return after a relatively short time as tolerances possibly grow requiring your 3000 rpm fix to get the compressor to actually kick in - once it’s working- it’ll stay working-
until the next day when it’s cooled down, and retracts and you’ve gotta go through it all again…-