Yes, it was working all along, ~2 years, and have changed "zero" items. I'm trying to determine if a clog in the stand pipe tonight. About to go take it out now.If it was working before, and you changed nothing, then there is a clog. If no clog, you must have changed something. Is your return pump DC? Did you increase its flow?
My return pump is a regular Eheim 1260 or 1262.