Need some troubleshooting help

About a month a go my canister filter went offline, I over filtrate and rum a couple AC HOBs on this tank.
I was actually away for 4 days. When I got back, cleaned out the canister,and no did it the usual way.
The next day the water got cloudy (milky) with foam. Figuring protein in the water.
Several water changes didn't help.
Water tests normal, no ammonia, no nitrites, nitrates close to 20, PH at 6.7.
Fish doing fine, but still can't get rid of the protein foam. The water is not cloudy as before.
I would say about 20%from being crystal before.
Don't see anything different on my end.
I do not feed burger. of any kind.
Tank has been running for 6 years.
I realize that the canister could have been the issue given that it was off for about 4 days from what I gather.
I added bottled bacteria and running the HOBs with Poly-filter.

Any ideas, or just give it time.

Looks like no other ideas

Hopefull just die off from the filter but from what you say the other filters picked up the slack. You can try to "mop up" the foam with some kitchen paper placed gently on the surface of the water

Thank you, problem solved!