I was trying to upload a 300mb video via the local police's web interface, a very important matter. I had to set my phone screen to stay on for 30 minutes and then leave the web browser open without touching it. Disabling all power saving measures makes not difference. This was the only way I could get it to finish uploading. I'm on a pixel 8 pro with grapheneos. Same thing in both Firefox and vanadium. I don't think it runs out of ram, the system is just too trigger happy. The battery still doesn't last all day anyway.