Ford Focus Mk2.5 1.6TDCi low acceleration

Hello, first time poster.

I've owned a 4/2008 1.6TDCi Focus for about a year now, and I am mostly pleased with it, apart for some quirky malfunctions the car throws at me every now and then.

For about a month nonth now my car has been having some peromance issues. From 1500 RPM up until 3000 RPM the car accelerates just fine, but after it hits 3000 RPM there is a noticable drop in engine performance.

I am 80% certain that this issue is not caused by the turbocharger, since I have replaced the Right intercooler hose and boost pressure valve, meaning that the boost system has been checked relatively recently. I am concerned that the drop in acceleration may be caused by the DPF being partially clogged, although after a 20+ minute drive at high RPMs there was no indication that the DPF was regenerating nor has there been any improvements in acceleration. No DTCs have popped up concerning the powertrain. I have reset and primed the Fuel Additive Control Module using FORScan, because the eolys liquid is propably good for another 30000 KMs. I have also replaced the crank position sensor because my engine would turn off after 3000 RPM.

Might I also add that the drop in acceleration only happens when the car is at operating temperature (1/4 up to 1/2 on the temp gauge) and seems to accelerate fine at and below 1/4 indication.

Hopefully it's something that is known to happen and there are people who have found what this issue is...