Firefoc browser issue with upwork&messenger&other

'''''Today:''''' ''' DevTools crashed many times, and I’m facing unusual issues. I cannot call through Messenger and cannot connect for video calls. Also, DevTools is not working, even though Firefox Developer Edition is quite good and healthy. Even Firefox is not working well. Please fix this issue quickly.''' '''''OLD ISSUE''''' My Firefox is using a lot of data; I don’t know why. I am not using Firefox, and it is not running in the background, yet it is always using the internet. So what do I need to do in this situation? I tried to stop the internet connection using outbound rules, but it did not work. It is still using the internet. What is the reason my browser has high data usage? I have high data usage; in fact, in the past 12 days, we've used 30+ GB of data.