After 2 weeks of constant resetting of my AirPods Max, forgetting the device, letting it drain fully, recharging it to 100%, and total silence from Apple Support on the matter, I finally discovered a solution that works.
Tools you'll need - a SIM ejector tool or paperclip. Removing the ear cups from the headband and physically reconnecting them worked for me and my AirPods Max is back to normal. There's plenty of YouTube vides that show you how to remove the headband.
Why it worked? I suspect is the latest firmware updated may have screwed up my APM and resetting with the buttons is merely a software reboot. By disconnecting the earcups from the headband, you actually disconnect the battery on one side to the other logic board. Reattaching them seems to force a hardware reboot and resync. Just need to pair them again with your iPhone/iPad and you're good to go.