@NetworkNerd said:

This was something @FiyaFly and I worked on together, and I believe he was the one who fully resolved it by changing the baud rate settings on the physical fax machine. But I can say for a fact that this setup worked and is still working today at the site in question.

good job 🙂

Stumbled on this, remember when Vipre was a thing? Boy have things changed a lot in the last few years.