We both cursed and prodded at it and threatened it with objects both blunt and pointy, to little avail. (We also checked the seals and adjusted both sets of cutoff flow meters.) I hit the internet, and tried another adjustment fix. No love.
Today due to various medical reasons I ended up WFH in the afternoon, so I decided to take another stab at it. To the GoogleMobile!
Me: Search: Toilet won't fill sometimes.
Google: Search results: Toilet never fills. How to unfreeze your pipes!
Me: No, pipes are fine, but I have to wobble the fill unit. Hmm. Search: Toilet only fills with moving lever.
Google: Search results: Toilet won't stop filling unless I jiggle the handle!
Me: NO, dammit! The fill unit won't START going unless I whack it one! Argh! Search: TOILET UNIT PHYSICAL FORCE
Google: Search results...
Me: JESUS H. CHRIST IN A RHINESTONE-STUDDED STRAIGHTJACKET!
Me: *Safe Search: On*
Me: Okay. Search: specific fill unit brand name.
Google: Search results: Troubleshooting for your unit! Fills slowly or occasionally not at all?
Google: Probable sediment buildup in feed tube. Remove unit cap, straighten a wire coat hanger and jam repeatedly into tube to remove clotted matter.
Me: BRB, GIVING TOILET AN ABORTION.