Ive seen this before.
Cam profile are typically more radical on intake side. The valve spring is not keeping the valve under control. Most of us don't have a spintron to test the valvetrain.

You have an unhappy intake valve train. Talk with your cam grinder about your intake lobe profile.

Some things they may tell you may surprise you. Seat pressure and weak springs kill parts. You are getting an early warning. I suspect you have too much valvespring for the lift. Meaning the valvespring is not being cycled properly. If you do not open the valve to .050" from coil bind the spring will dance around. For years we set spring height based on a psi for seat pressure or the manufacturer reccomendation for installed height. PAC has me setting spring height based on full open spring height. Amazing the difference it has made in valvespring life.

I regularly turn 9,000 and get incredible life.