orydeatemi Bandwith and outages-wise, re-downloading both a stock image and GrapheneOS would probably take half a day.
A factory reset wouldn't require downloading anything. Not sure why you'd need to download the stock image unless you wanted to test if the same happens on the stock OS. If your carrier blocks using hotspots, then it definitely won't work on the stock OS.
That said, while factory resetting takes very little time, backing up apps, restoring them, and setting everything up again can take quite a while depending on the setup.
orydeatemi The workaround described here works, hence my sneaking suspicion that it might come from something upstream.
orydeatemi rebooting with airplane mode activated, and THEN activating Wi-Fi
These things seem strange to me. I agree that there might be some upstream bug, but I am not sure how carrier config can affect wifi like this. I'd think that the best way to figure out what's really going on would be by seeing the full system logs.