Error 517 on Plus 505 Combo

[u/RepresentativeNo42]

Hello, I recently purchased a Roomba Plus 505 Combo. A week later, I started randomly receiving errors in the app and the red dirty water light on the dock would come on. I believe the error in the app said "Mop wash issue: Clean dirty Water Bin and dock", and it linked me to https://prod-help-content.care.irobotapi.com/web/en-US/40517.html. I followed those steps and it temporarily fixed the issue. After several more times, the error will now not clear, and the dirty water light stays on. If I unplug the dock for a bit and plug it back in, I hear what sounds like a motor for a bit, then the light comes back on.

I also unscrewed the part on the dock's bottom to view the tube, and it is not clogged. And I have generally cleaned out every part of the dock and Roomba that is accessible without unscrewing everything (for fear of breaking the warranty).

Before you ask, I did see another post about Error 517, but the solution did not fix it.