Is the problem still faced ?. If yes, Please let us know so that we can further deep dive into the issue.
I'm having this same issue: Event based rule is firing perfectly in chrome but not in firefox. I'm using 3rd party zaius script
Please close this issue. We were able to see the data in sitecatalyst. Only we couldn't test in FF debugger.
Can you please share your DTM company login details and the test Url in a private message so that we are to reproduce the issue at our end.
Thanks & Regards