The Tribunal oversees conflict between pantheons.
The 5S are avoiding them very explicitly over the Nyjyr Ennead incident, and the Eris incident which is an affront to the Olympians, and the whole Orcus thing is also a bit precarious, while Orcus and Doom are not signatories, Orcus is by birth an Olympian. Zeus & Hephaestus could make an issue of it.
Hephaestus is a member of the Olympians, the Nyjyr Enneand and a few other signatories, he could cause real problems.
Tiernon etal have been trying to keep things rather hush hush. In many ways, Phaestus has a lot of keys and if he is meeting with a tribunal agent (note that Stainsberry came from Isle of Doom, where Phaestus is) Tiernon is going to suspect that Hephaestus and Orcus are bringing charges to the Tribunal.
Obviously, they are not, yet, but Tiernon doesn’t know this.