Rocker oiling or lack of .

Keep in mind if these are “normal” HS rockers(solid adjuster screw), having “pushrod oiling” will only be lubing the adjuster screw and pushrod.
There is no way for the oil to get from the pushrod to the inside of the rocker.

Unless the rockers have some oiling provisions beyond what is typical for HS, I would want to make sure the std head oiling is functioning 100%.