As you've already mentioned, any filtered fitting to prevent trash migration should be checked. But before that, I would verify my pilot pressure. Measure your source at the self-pressure-reducing valve. Then I would compare that against what's in the manifold feeding your RCVs and then see what you have being delivered to your spool caps. I know this sounds like a lot but it will help you narrow your search. If pilot oil is correct and proportional to your input of function, then I'd be looking at pump pressures and the potential that you have weak travel reliefs or a worn out turning joint that might need a reseal. Since only your travel is affected, it seems very likely. And if your hitting higher pressure with arm-in with power max than with travel, that kinda says something, if that's what you come up with. Is it one side or both?
