Board-state included:
- Ayula, Queen Among Bears
- Lumra, Bellow of the Woods
- Roaming Throne (with "Bear" as selected creature type)
- Maskwood Nexus
- 2 Snow Forest, put onto the battlefield by a Roaming Throne doubled Lumra trigger

Maskwood Nexus suggested using two tapped land for paying it's cost (I believe the very lands fetched by Lumra). When the shapeshifter entered the battlefield, the expected result was two triggers by Ayula (again, Roaming Throne doubling). However, instead of those triggers going to the stack, they auto resolved, with the first one setting two counters on an unselected Ayula, and the second one resulting in a fight between Ayula and an unselected (undesired) creature. Needless to say, it cost me the game.

To summarise:
- Game suggested 2 tapped lands for paying an activated ability cost (my hypothesis is those lands being "bugged" due to the interaction between Lumra and Roaming Throne being programmatically broken)
- The expected triggers in resolving said activated ability auto-resolved without player input, instead of going on the stack.