I would replace them one at a time and see what happens. This is troubleshooting, where you’re not sure where the problem lies. It’s obviously not the anode. Don’t put the anode back until you’ve checked the filters.
Apropos to troubleshooting, we do have a couple of stones still unturned. Does it at every tap and equally bad at every tap?
And what brand water heater is this? Could you tell us the serial number? There is a slight chance it could still be an anode issue.