I'm in the same situation. It's sad that you can't play in friend challenge mode. I hope it gets fixed soon.

Well it seems wizards doesn't give a **** about historic brawl players. I feel it's the only thing worth playing on arena. **** wizards of the coast

Stop releasing new sets and fix this basic bug thats been around for years now.
If you have abandoned brawl then remove it from the game so we can all abandon magic.

Brawl players generally don't want to go near standard.

Same issue. Friend has same issue. Clearly a bug.

It's just incredible. You can challenge a friend by playing standard deck but for brawls it's only the "Friend" rules! Are you joking ?!? What's the **** is wrong with you ? Why did you have removed this game mode ???

Same issue, only standard decks show up, and when I double click my brawl decks they and click on the graph to check what type of deck it is, it shows it as a standard deck, and the commander does not show up.
Also put in 100 card historic brawl challenge.

same issue

Me and my friend have the same issue. Please fix this

Same issue, Tried changing multiple parameters such as coin flip winning and all that but cant play brawl.

When I challenge a friend to a Brawl game and am prompted to select a deck, only my standard decks are selectable. My Brawl deck is marked with a red !. I can't select it. If I select a standard deck I'm told Invalid Deck Type and kicked out. This has been going on for at least two patches now. Please fix it!

same thing happened to me it tried to make us choose a standard deck for brawl then said invalid deck type

Same issue. I have tried this on all friend challenges, and either it reads "network error" and fails (generic historic challenge), or is an invalid deck (Brawl). log file attached for Mac.

Whenever I challenge a friend to brawl it says my brawl decks don’t have a commander. When I exit the challenge and go look at the deck, it shows I have a commander.