There are two other posts here about this problem; I’m wondering if this third post points to a solution. Posting in the hope that someone more skilled in this topic has insight.
The two posts about this problem:
The code sample Glitch :･ﾟ✧ shows the same problem, so I think it’s not a coding error.
This post refers to proxying websockets… suggestions on how to do that?
I can’t tell if this stack overflow q/a has useful information: