OE error says the washer didn't drain within the time limit (I think max time is 10 minutes to drain.)
When mine did that I followed the same path as you, clearing the filter, but I still got OE intermittently.
I removed the front and found the drain hose at the bottom of the gasket was blocked. Both the nipple on the gasket and about an inch of the connected hose were clogged with a tiny chain (part of a necklace).
I wouldn't have expected a clog in the spot to prevent proper draining, but we 're not getting any more OE errors, so what can I say?
-ps The 2 metal loops that hold the door-gasket in place use a special tool to put the loops on and off. I've seen workarounds, but with the $12 tool it's dead simple, so I recommend getting one.