I have the same problem exactly on PC. I can play everymode in fifa18&19 including co-op but cant play friendly season with the same person i play co-op. Its not the connection quality problem at all. Because i dont have lag in other online modes. EA has to fix this silly problem instead of copy& paste answers. We are paying to play this game so we deserve some real customer services.
I have the exact same problem on the ps4 with my friend and I been trying to find a solution for it, for months now and cant find anything.
@PabloTescoBar695 This issue can be caused by several things, from a communications ban through Sony/Microsoft, restricted NAT, lack of Xbox Live Gold/PS+, Privacy settings on the console or being on a child account rather than one aged up for online play.
Firstly, I would ensure that your Xbox Live Gold/PS+ hasn't lapsed recently.
Ensure your account is in good standing, even a communication ban will remove your ability to play ProClubs/Friendlies.
Try removing the Profile from the console and redownloading it.
Check that your Privacy settings haven't changed on the console - they should be set to Adult Default on Xbox.
Finally, make sure that your ISP hasn't assigned you an IPv6 address recently, as they don't play nice at the moment with most games.
Check your ports in your router.