Hi

In the Android Settings app under Applications, does Firefox for Android have permission to use background data?

Yep it's got permissions for all data and has usage logged for background. Of course that's only on WiFi seeing as it won't work on cellular.

Yep it's got permissions for all data and has usage logged for background. Of course that's only on WiFi seeing as it won't work on cellular.

The two errors I get are "connection reset" and sometimes "proxy server refused connection" which doesn't make sense because I'm not using a proxy.

There are at least three threads in this problem floating around. One has reference to "version 115.x should have fixed this" (would be nice to get info on what the problem was...) But as with others it's still happening do was either not fixed or has been reintroduced.

Ok this gets even weirder; I saw the notes about version 117 that referenced fixing a problem like this caused by corrupted startup cache and thought maybe that would resolve it.

It didn't but I then tried switching the SIM card out and found that with my SIM in my wife's phone Firefox works, with her SIM in my phone it also works but with *my SIM* in *my phone* Firefox cannot load any pages on cellular.

So that points to....I don't know what. Is something in the browser somehow tying config to the SIM card but only on my device?

The threads that mention I think refer to a wider problem that impacted quite a few people. If htthatnwas what you are experiencing, we would be seeing many questions about it right now.

As far as I am aware, Firefox for Android has no knowledge of a SIM - it works perfectly well with or without one.

Yeah this is the crazy thing. Same thing with it working on WiFi but not cellular: it doesn't make sense from a browser config point of view.

I attached a usb debugger to a nightly build install and nothing of any use logs. Web requests just sit there for a chunk of time then fail with ERR_NAME_NOT_RESOLVED or ERR_CONNECTION_RESET.

But how on earth would that vary with SIM+phone...

Has that SIM got stufficient mobile data paid for on it?

What version of Android is installed on the phone?

Yep 60gb of data available and everything else works - chrome, edge, tidal etc. Literally the only thing that has a problem is Firefox :-/

Just tried again with two SIM cards in; one works fine, the other Firefox can't finish loading anything and gives one of the errors (or once a proxy error when there is no proxy in use).

Further to my previous question, what version number of Android is installed on the phone?

I gave up and factory reset the phone, and Firefox now works. Given that the error wasn't data/network related it must have been software, either in android (seems unlikely given the error messages) or some issue in Firefox related to the way it handled the connection (everything else worked so this was not specifically a handset issue, it was definitely the browser). I was fed up trying to use Chrome or Edge so despite the headaches I am still a Firefox user!

All versions were latest, including Firefox nightlys as mentioned.

Glad it is now working, thank you for letting us know.

I tried all the solutions mentioned above, except reinstalling Android completely... I really didn't want to do that. So I looked around a bit more. First of all, there are lots of suggested solutions, but rarely one that works (except reinstalling EVERYTHING...) some people just reinstall Firefox, but in most cases, it still doesn't work.

In my case, the solution was in the APN configuration on the SIM card. I deleted the address configured for the proxy (192.168.210.1) and the port (8080), leaving the fields empty (not defined). Now everything works perfectly again. I hope this helps someone!

Hey Yves, that is an incredibly well times post because this literally *just* started happening again today and the same thing you suggested fixed it.

So basically the error of "connection refused by peer" or "proxy server refused connection" and the inability to load any sites on an otherwise perfectly functional phone points squarely at the apn proxy setting and means that there *is* a Firefox bug in relation to how it is handling mobile provider proxy settings!