I just happened to try some upgrading on several rbm33g mobos which have r11e2PnD cards in them. Tried 18.05 through latest 19 and all seem to have broken ath9 drivers reporting the following error:
ath: phy0: Unable to reset channel, reset status -5
The more I processed eliminations I discovered its not only the cards, its the boards as well. One mobo works fine with the one specific card, while not working with the other board, nor other card, etc. Where I discovered this was on 19.04.0
I see Denis Kalashnikov has been working on patches for this. If someone can tell me more what to look for I'm happy to share whatever information on the boards and cards I can. Upload photos of the differences.