There is a lot of randomness to who you face in GW, especially in those later nodes. I believe that the teams are based only on GP of the team, which means that there can be some pretty significant swings in difficulty of a given team.
There is a segment in time where those teams get pretty powerful and can be quite difficult to beat, which is where you are now.
GW wasn’t always like that. In fact it used to be that it was (maybe?) glitched as the node 11/12 were ultra easy teams. The devs fixed that eventually and it became what we have now.
Many of us who started early only had to endure that window for a really short time, and had enough of a roster built up (before the game mode switched to that ultra-hard) that we barely noticed.
It will still be a relatively short window for you as well, although I get that it can be very frustrating.
Just keep building up more teams and accept that at times you won’t clear GW. It is what it is.
I doubt that the devs have any plans to “fix” it because it is only an issue for players within that window.
