Jake choppy when oil above 230

[EngineEer]

So I have a cm2250 deleted cant wrap my head around if the ecm is failing or im missing something simple here

The jakes are choppy/weak right after a long pull, oil @ 230-235 degrees, and oil pressure seem to drop to 30-33psi when jakes activated. I need to manually fan on to cool the oil down to 225 or less and then my jakes are strong again

I change oil 250hrs conventional 15w40 rotella, it does seem worse when i get close to 200hrs on my oil (oil breaking down)?

So far
-new crank and rod bearings, and new oil pump OEM cummins parts. That got my oil pressure back to normal 35psi spec, when warm at 235 degrees. Was about 31-33psi with old bearings and pump at 235degrees before
- new wiring harness and solenoids in the head - OEM Cummins parts
- wiring checked good at 0.1 ohms from passtrough connector to ECM for the 2 jake solenoid
- new ground terminals next to ECM
- installed a rebuild kit for jake heads with new spool valves and springs… same issues
- swapped another set of full rocker shafts/levers/jake heads from another truck… same issues
- new exhaust back pressure sensor and wiring tests good
- no boost leaks and no exhaust leaks

Any ideas? Im wondering
- bad ecm (drivers for 12v for the jake solenoid are failing)?
- oil thermostat failing, cant make up its mind on being open or closed?
- injectors leaking a small amount after pulling
- havent tried new switches for engine brake, but its good on the scanner, 100% engine brake level , and switch ON at all times. Maybe I should try that

When it does get choppy i have seen driver solenoid #2 switch from on to off randomly on the scanner a few times, and solenoid #1 stayed consistent ON.

Would love to hear some ideas. Ive read some other posts on here about worn rockers shafts but i dont believe its the case for me here