Re: Grand Arena Bug - Banners Incorrect

So from the swgoh.gg data, your opponent only defeated 6 squads vs. your 7. If you both full cleared, that means you forgot to set a defense, likely in the territory featuring three squads. This would automatically grant your opponent 64 banners. You wouldn't be able to see that scrolling through the individual attack banners, but it's reflected in the total score on swgoh.gg at the top, where your opponent does have more banners than you.

The exact numbers will be a little off as there's an error on the website calculating ship banners, but it looks like your opponent did win because of the extra banners from the missing defense (+64 for them and -90 to you).