Whirlpool Duet Sport F-20 only during clean cycle

Hello, I seem to be having a strangely specific error code: When I run my Duet Sport on the "clean washer" cycle, the washer makes it to 20 minutes left (on the countdown clock) then trips error F-20. No other cycle brings up the error.

Troubleshooting thus far:

-Verified that both hot and cold lines have pressure and put out water
-Hot & cold lines turned all the way on
-I Do not have flood proof lines, lines are not kinked
-There is no blockage or debris in the inlet screened cap area
-black hose from pressure sensor clear
-cleaned out drain filter (bottom of washer)
-shop-vac'ed the drain hose
-Run diagnostic, only error F-20 came up, diagnostics completed fine
-Run manual diagnostic, completed fine

Any help would be much appreciated! Thank you!