Reef Octopus 6" Pinwheel In Sump Skimmer OCT NWB150 skimming issues

I have had this protein skimmer for some time, though a tank upgrade was delayed so it sat idle for some time. Since installing it on my roughly 145 gallon system, it has given me issues with skimming properly. It was eventually discovered that there was an issue with the impeller shaft, and it was replaced. Even since replacement, it has not skimmed properly for more than a 24 hour period. This can sometimes be remedied by taking the pump apart and sitting the impeller again. Every time the rubber stopper at the end always gets stuck and has some difficulty being removed so the impeller can be properly reassembled.
Has anyone heard of such issues and know of a fix? I've tried pretty much everything. I'm aware this is a great skimmer, I would just like to have the performance out of it that everyone else is able to report. Taking this pump apart daily is absurd.