You just wont believe how many Devs are not reacting to Bug Reports in any good way, and just ignore the garbage that happens, even though the fixes are trivial to implement on their end… And I am not even talking about Mod Devs, I mean ALL TYPES OF SOFTWARE DEVS!
Edit:
So I tested it in my own World, and here is some fun findings:
Lamp + 1 Wire + Lever = Perfectly fine
Lamp + 2 Wires + Lever = Blinking Mess followed by Game Freeze.
So it should be an Issue on my end for sure. Might be the Opaque Block Detection for Redstone Transmission reacting to the Lamp that is somehow an Opaque Block.
Edit 2:
I should mention that until the next Release is out, you can attach a Vanilla Redstone Repeater to the Wire (like a Cover) to make the Wire a One-Way Output resulting in the Thermal Lamp not being able to Loop the server to death anymore. So this might be a nice temporary fix for you. ^^
This also works with Redstone Torches but would invert the Signal. 