Launching the new C3 runtime.
I couldn't isolate it, after checking the internet too, and seeing the number of issues with physics of a similar nature, I concluded the best way to fix that was to not use physics behavior at all. (btw the error is "c3runtime.js:2 Uncaught (in promise) TypeError: self.Box2DWasmModule is not a function" and already happened previously on my project a long time ago and I had to reach the same conclusion)