Help with a crash with Combine and GCD on swiftUI app

So I am new here, but familiar a bit as one of my friends did the bootcamp a few years ago. I have a question I'm not sure Stack Overflow is the right place as its a bit involved, and so just thought I'd post it here.

The details are in the link below (just look at the first bug description, its the most important), the gist is some calls are made on newly created Dispatch Queues in GCD to do work in Combine, publisher results are saved in a set called "disposeBag" and when this method is called it sometimes crashes.

Whats curious is this used to be very rare, now it happens almost all of the time making the app unusable and I'm not sure what has changed. I did not write this particular code but inherited the project and am trying to fix it (I do call this method in other fixes I made, so could be when and where I call it that it doesn't like, but the method itself should be more robust to not crash)