Unable to connect to Holographic Remoting Player

[ProgrammingKiddo]

I know this problem was already considered an issue ( #9465 ) and it got solved, but I'm having the same problem even though I think I have everything I should.

I intended to ask about this in the Slack, but it seems the automatic invitation sender is not working atm (it throws error 500 just now) so I cannot join.
I thought it'd be a better idea to ask about it first rather than straight re-opening the issue.

I'm currently connecting both the PC and the HoloLens (Gen1) to a mobile hotspot created by my phone (could this be a potential issue?) so they're both on the same network. I've attached some screenshots to see if anyone spots something I'm missing, as I'm still fairly new to this environment and I don't fully understand what most things mean/do.

As can be seen in the screenshots, I'm using Unity 2021.3.20f1 and MRTK 2.8.3.

Thanks in advance!