You have created Acronis bootable media under macOS 10.15.5
After you recover the system using this bootable media, the machine does not boot.
Issue in macOS 10.15.5.
The chflags() system call can no longer set the SF_FIRMLINK flag on a folder on an APFS volume. Rather than fail with an error code that could be detected, it fails silently – it exits with a success exit status, but silently fails to set the special flag. You can find more details about this bug affecting other software in this blog post.
Install macOS 10.15.6 and re-create Acronis bootable media.
(!) Only version 10.15.5 is affected by this issue. If bootable media was created using an earlier version, e.g. 10.15.2, it is safe to use.