Error 999 "Vault Version 999 is unsupported"

IOS = 2.4.8 build 1075 (TestFlight)
Windows = 1.8.0 (msi-4440)
MacOS = 1.8.0 (dmg-4440)

Vault lives in MS OneDrive

Can open vault from Mac and Windows

But from IOS, error is
Vault version 999 is unsupported. This vault has been created with an older or newer version of Cryptomator.

Is it simply that the Testflight version should never be used other than for…testing and will always cause issues with existing vaults on other platforms?

Related to:
another 999 error on all updated versions of Cryptomator