Update:
I am a bit wary of deploying this unit with pre-release FW, but we gave the 8.1.3 build 5054 a whirl.
Aside from however the RC 1 version of the FW works in other aspects, at least this particular 8.1.2 issue is gone in 8.1.3 RC 1.
Resolved in other words.
Cheers,
Z