My average intake on a slow evening was a 9 or 15 pack of Coors pint cans, so 144oz or 240oz.
These days, I stick to water. However, you probably have never seen someone who can consume as much as I can, casually. I’ll drink two pints of water at the refrigerator when I go for a glass, then fill that again and go back to doing whatever I was doing. (I won a ton of beer drinking bets. A pint of whatever is easily drank at between 3 and 5 seconds. My ability to consume any beverages is basically superhuman and likely a contributing factor to my brush with alcholisim.)
Check your flatpak permissions for starters.
Flatpak apps operate more like containers and not a full blown sandbox, unless that has changed recently.
This is an interesting blog post on the subject: https://hanako.codeberg.page/
Also, try
flatpak run org.mozilla.firefox
to see if you can launch a browser manually.Disclaimer: It’s been a bit since I have used flatpak, so take that into account. However, I do work in security by trade, so my quick notes may point you in a decent direction at a minimum.