My husband and I can’t play together

What platform are you guys on? My girlfriend and I play bf6 together on the same network (both hardwired), but I'm on Xbox and she's on PS5. We've had AT&T fiber Internet for about a year and a half and when we first got it, I noticed the "NAT" status in my Xbox's network settings had become "strict" but when we had Xfinity cable Internet the NAT status was always listed as "Open".  I know this can affect matchmaking so I had to ultimately go into the settings for my fiber gateway, turn off the built in wifi, set up the "ip passthrough" mode in the gateway's settings, and hooked up an external regular wifi router so that upnp would work correctly (because my Xbox's network settings were showing that upnp was also not working when I was using only the AT&T gateway). Then my Xbox's NAT status went back to "open".  Not sure if you're using fiber Internet or if your network NAT is restrictive or how to check that on anything aside from Xbox or PlayStation though.

Thank you l! We ended up doing all of that to but we use PC and nothing worked, so my husband had to use nord vpn and it worked that way 😮‍💨

Interesting.  My buddy and I just played on two different PC's together at his home, earlier today.  Both his machines are Win11.  When I built the new machine for his bedroom, he left his old one in the living room, just for occasions like this.  So we can play BF6 together.  Both are on the same subnet, the old PC (8700K/3070TI) is hardwired, and his new PC (9950X3D/5070TI) is rocking an early WiFi 6 (802.11 AX router.)  Using a VPN is going to kill your husband's latency.  Just for giggles, I'd try sending one machine through WiFi.  It won't take but a few minutes to try...  In all my years in IT, I've seen MUCH stupider things work.  I can tell you without a doubt, that two machines on the same subnet can play together.

Reading again what KlootonicPlague wrote about NAT...  XB and PS might be using different ports, whereas Win PC's would be using the same NAT ports.  This would be a programming failure on EA's part.  I'm headed back to my buddies house this weekend, I'll head down to the basement where I store my 'magical box of cables' and find him an ethernet cable that will reach his room.  (It's a big box.)  Otherwise, I have a ton of cat-6E cable and can build him one.  This could be as simple as being on different subnets, and adding a route to (each others networks) on both machines?  I'd suspect this is EA's fault, for kissing the, I mean cozying up to console manufacturers, instead of the gamers who BUILT their company.  I'll post back with what I find this weekend.

I had the same problem with my son. Turns out our EA accounts were the problem. As they were linked on everything we gamed on. I created a new EA account and had to start over but it worked 

That's too bad that none of that worked, but I'm glad to hear you guys at least found a work around with the nord vpn.