We’re not Apple. We’re other users.
You have already received the disabled-reset instructions from Apple.
Presumably these: If you forgot the passcode on your iPad, or your iPad is disabled - Apple Support
These instructions clearly did not work.
At most, we can suggest following the same official instructions.
Maybe trying a different Wi-Fi network, ensuring current iTunes or macOS patches, or the restore, and such.
But these are the same instructions that did not work.
Something is not quite right with this iPad, or with the reset sequence for this iPad.
Contact the folks at Apple Support again, and request further assistance.
This may well require you to bring the iPad in for Apple to (try to) reset, for instance.