Yeah, I agree the OP has a different issue without having access to an actual Atari, just thought I would share for those who care.
The Virbatim DD disks are 310 magnetic particles per inch with a coresivity of 620 oersteds…whereas the Virbatim HD disks are 670 magnetic particles per inch with a coresivity of 720 oersteds…so yeah they are not exactly the same, but it’s not really a big deal if you back up your disks on a regular basis.