CM871 - camshaft bearing issue

[PekySVK]

hello, i have 2011 CM871 i replaced cylinder head on 1M mi . around 1.2M mi i start having issues with crankcase pressure so i saved some money and did inframe (cost of crankcase pressure were broken piston rings ). let the machine shop inspect cylinder head sense was of even it had less than 200k on it. they convinced me that i had to upgrade all my valves, springs, cups, bearings and seals. everything was great and put to gather and truck run great with no issues. put 2000 mi and i spun injector cam bearing #1. ... i brought it back to the shop take it a part and i found no explanation why it happened. machine shop repaired cylinder head. everything was fine for 6-7 hours of truck running with no load on parking lot on idle . with oil pressure 32psi spun bearing #3 on injector cam . i don't know where to start looking . what could be my problem of spinning injector cam bearings .