Error code 1:85009S

For those still figuring this out and stuck, try troubleshooting it this way:

1. Try to create a fresh account with EA, then download BF RedSec with the EA App (it's free!), and see whether the error is still there (shutdown everything else like Steam). If it is, that's how you eliminate the possibility that this is account-related, so you can ignore all account relinking troubleshooting steps. 
2. For networking-related, you can try a combination of DNS change to 1.1.1.1, 1.0.0.1 or 8.8.8.8, along with ipconfig /flushdns , etc. etc. as others has pointed out. You can also try Cloudflare Warp though highly unlikely that will resolve the issue. Also see whether bufferbloat is a potential issue https://www.waveform.com/tools/bufferbloat
3. Try creating a new Windows account 

For some of you in the same boat as me, no troubleshooting steps so far has resolved the issue for me. And I noticed that this started happening since the change from Origin to the EA App. For some reason, all EA games would disconnect after 5 minutes of gameplay. So I figured the problem is some anticheat software issue. Ultimately, a full Windows reset resolved the issue. I just backed everything up, then do a full reset, install my LAN, Chipset, Audio, GPU drivers, install Steam, BF6 and it now works flawlessly

2 Months and counting the ERROR Still Persists! So many people having this major problem and still after so long EA Can't able to fix there problem, thank god Their REDSEC (Battle Royale) Flopped! they deserved it. We purchased Pre-Ordered a GAME that we weren't able to play this whole 2 months! What a Big Trash Scam the whole TEAM is, no acknowledgement no response, nothing ZERO zip NADA. Shame to the whole team of DEVS you guys let the whole community down! FRESH OS install is not a SOLUTION Period.

Still having this issue.  Crazy that I can't get a refund either.