That towel trick is pretty smart honestly. My roo used to start at 3:30am and I tried a blackout curtain clipped over the roost area, shifted him to 6am. Light really seems to be the main trigger for most of them. Did you have to adjust the towel every few days?

...but see the thing is, even with the right paper and tons of water, you're still heating up that clear if you're going at it for 15 minutes straight. That's what the old timer was probably getting at (and what I finally figured out after it cost me a couple of jobs). I'm curious though, how thick are you spraying your clear typically? Because if you're laying it down heavy enough, three quick passes with 1500 should be plenty to knock down the peaks and not touch the valleys at all. That's what changed for me (and why I think that "more is more" approach to wet sanding is actually hurting people's final results).

Might be overthinking this (just a little).

But don't you think it could just be coincidence and not some special magic week? I had a similar experience once but later realized the weather patterns just pushed birds into my area for a few days. It was still AWESOME but I try not to overthink the timing.

My buddy had the exact same problem with his LG. He cleaned the filter too and the OE code came back after a load. Turns out the drain hose had a kink behind the machine that was slowing the water flow. He straightened it out and it worked fine for a few days then the code popped up again. Ended up being a partial clog further down the drain pipe where it connects to the house plumbing. He had to snake the line to clear it out and that fixed it for good. Might be worth checking your drain hose and the pipe it goes into.