So now I'll have to reinstall ESXi 6.5 to get around this issue. Unfortunately, when I discovered this and found the instructions to rollback to previous version, both bootbanks say they are 6.7 and cannot be downgraded or reverted. Search your raid card again, and see it probably says 6.7 supported. Search 'LSIprovider' on the compatibility check page to see the 6.5 U2.
My raid card reports supporting 6.7, so you think all good, right? Nope, not if the LSI provider functionality is no longer supported. Messed around with different versions of the SMIS and lsi provider files, but ultimately I believe the issue is that the LSI Provider support has ended at 6.5 U2. I just ran into this problem after upgrading from 6.5 to 6.7.
