Is this your first time with hblink3 (that is, the previous installs were HBLink on Python 2.x)?
The only difference I see between the two version (HBLink to hblink3) is that the salt for the SHA256 hash is generated "similarly". That salt generation might be enough to make it so that it doesn't match between the versions.
I've never had to support someone who was running HBLink and having it connect to HBLink3, and I would've figured this would have come up as an issue prior to this, given how deeply Cort was involved in both projects.
You should totally be able to host HBLink and DVSwitch apps on the same box.
Randy Hall AA6RH (not K7AGE, quit asking) 😁