Error code 1:85009S

I had the same issue, playing via Steam. 
I read in some forum that it could be related to anitcheat falsely detecting some software or drivers in the background tried changing dns to google and so on nothing worked. 
On wednesday a windows11 update  started to block the driver "asio.sys" and also killed my DNS-Client so I had to manually enable DNS in the Registry again (maybe disable,  enable and clearning the dns cache helps). 
Since then I was able to play two full rounds without disconnects :-) (I did not try more yet).

Maybe this helps someone.  

24 days passed and this **bleep** is still happening!

I'm having the same issue. It also happens in FC26. Good job EA, now you've essentially blocked me from buying any EA game that requires an EA server connection (which is basically every game).

After refunding Bf6, I just tried Redsec, but I'm still getting this error message. I get kicked out, see this error message, and after a short while (around 5min.) I can log back in without having to restart the game or anything. It's really strange.

I was getting this error for about a week. I could play for 5 minutes thn game kicked me out showing this error. I tried almost every troubleshooting method I could find on the net, nothing worked, finally what worked was a fresh windows.

On a 200gb partition I install a 2nd windows 11, where only things I have are nvidia app, steam, discord, edge and BF6. Now when I want to play, I just boot that windows. I know it is a hassle, but at least I can play normally. I played more than 40 hours without any error now. 

(img below is from my main windows, so it is not installed)

It's just inacceptable, you must fix this problem, i kept for 2 days being disconnected for no reason to any multi game i am playing just 5 to 10 minutes after i start it . At least tell us you are working it out before blacks ops 7 pop up and still your community because of a lack of quality and answers .

I did a PC reset and that worked for me.

I tried all other troublehsooting steps and nothing worked.

DNS, NIC reset, run as admin. install game on C:\, disable AV. etc.

Reset is the fix.

Resetting is not a fix. 

The reason it isn't a fix is because it doesn't address what was causing the problem in the first place. It seems clear to me that this is from something in Battlefield/Javelin conflicting with something on our machines. There is a good chance that it is some other software. If you happen to download that software again (it could be something widely used), the issue will re-appear.

All resetting does is turn your PC into a Battlefield 6-playing-machine because, if you do anything else with it, you might recreate the issue. 

EA needs to determine what the cause of the issue is and adjust. THAT is a fix I'm willing to accept. Or, yet again, just accept my refund requests.

I agree is not a fix but is a work around. I did a clean installation on my windows and work for me as work around. I’m installing all the software that I have before and that I need. At this point when I install a software run the game for a bit and see if anything happens so we can identify what is the issue. So far nothing trigger the same issue so I was either some breadcrumbs left by a software that the anti cheat didn’t like (my guess is anything work related 😂) .

so if people don’t mind and have backups for what they need a fresh windows installation is a good workaround. 
if after the fresh installation when you are installing other software and the error come back you may and should post here what software was it. It will help the anti cheat team to identify what is it and white flag it

Still a major game breaking problem with no support help. verified with support its a problem on there end.