If your circulation isn't changing overnight then there's a good possibility the clown hasn't found a place to sleep yet and is not distressed other than lacking a bed.
For the food not being eaten, try soaking some in a garlic additive from your LFS.
Once they start eating it, wean them off the garlic.
And try using fortified brine shrimp as the basic stuff is lacking in nutrition.
Koodos on the pump/flow changes, but for now I'd really like to see your return nozzles making distinct patterns on the surface. Until you clear out the excess bacteria the water will be lacking O2.
Even just until the water clears, be aggressive with that surface agitation.
And I think you're right about your water quality being fairly good to just fine as the rest of your fish are acting normal.
How are you utilizing the Carbon? Bag, reactor ... ?
My last tank re-start I put it in a bag and then directly into my sock.
My bacterial bloom went away in maybe 24 hours. Then I removed the GAC (Rox 0.8) and all was good