Data Disk not selectable after restore

Hello all.
I restored my Home Assistant Blue.
It had been having bouts of restarting over and over until I pulled the power. It would then run fine for severals days, then it would have another episode of restarts. I disabled integrations and apps. But, could not find the culprit.
I replaced the boot eMMC with a newly imaged one, then restored an automatic backup.
Everything works, except, the 1tb MicroSD data disk is not recognized.
It appears in the Move Data Disk drop down, but is dimmed out.
I've checked the filesystem from another computer and it's undamaged.
Is there a way to make it available for the system?
If not, is there a way I can recover my media from it?
Thanks!