Cat 301.7D CR – Boom operation not smooth?

Recently picked up a used (~1500 hours) Cat 301.7D CR mini excavator. I've used other mini excavators before (other Cats and Wacker Neuson rentals) but with this cat 301.7D CR it seems to have an issue where the right control operation isn't smooth and will drop or pull harder then expected, but its not consistently happening so it is hard to predict. The boom will operate as expected but then suddenly it seems to move more then the input, so the bucket will drop or the boom will pull in quite fast or if you are digging it will pull the machine more them the stick input would suggest. It isn't unusable, however I need to be mindful when operating as this additional movement compared to the stick input can mean hitting surrounding objects with the bucket/boom or pulling the machine excessively when the attachment is digging the ground or pulling on a fixed object under the ground. It doesn't appear to be related to load on the boom so its a strange one to diagnose. I've tried to pinpoint if there is a particular operations on the controls that causes this but can't seem to isolate, but from memory it seems to be boom operations and not stick operations. Any ideas what could be causing this issue?