What Am I Trying To Do?

I have a PC at home and I want to be able to SSH into it from my laptop.

The Problem

I have done this a few times before so I'm not sure what the issue is exactly but basically, my port forwarding *does* seem to be working but I cannot access my router's IP from outside my network.

I get my IP from something like whatismyip and while pinging it from my PC (which is connected to my home network via ethernet) works fine, when I ping it from my laptop which is connected to my Phone's hotspot, I get no response.

I am not sure what the problem is here, I tried this some time ago before my student housing switched to TpLink and it worked fine. I'm not terribly familiar with networking so do let me know what information might help you debug this, thanks in advance!