Yeah, LevelQuick product is great! I used it in my bathroom renovation, prepped up thoroughly by sealing and priming. The result was flawless and tiling over them is very easy.
Same issue with mine. Mine’s issue was the vent pipe was clogged with lint, I cleaned it thoroughly, then it worked again, good as new. Just try checking it again.
I think it’s an airflow issue because you said that you already cleaned the vent, there must be a clog somewhere else. Check exhaust pipe, it might be block, the one outside.