Hey @KH,
Apologies for the delay. Took a while to attempt again, but we are getting:
"Unbinding Failed!' Selected Networks failed to unbind from template XXXX as some of the configurations could not be retained."
The actual unbind post request gets returned for 400 (Bad Request)
From my understanding with talking to support there is not a configuration retention issue preventing the unbinding, but a known sync issue with dashboard that is still unresolved for a number of networks. I'd personally prefer not to nix the whole thing and rebuild as that would require substantially more downtime and this is the FW at our main DC. But I'm also lazybones. 😉
I've got HAR captures, and screenshots of all of this in the case w/ support. Shoot me a PM and I can send you the case number if you wanted to take a look.