I was playing draft and had 18 life with Ragost, Deft Gastronaut in play and 2 2/2 artifact creature tokens, my opponent attacks me with a 22 trampler and 2 other creatures. I block the non-tramplers with both tokens and click assign blocks, hoping to get a chance to activate their food ability given by Ragost getting me back up to 24 life, and NOT DEAD. When the game immediately assigns combat damage. And I die on the spot.
There have also been other times something similar has happen to me and I'm left standing there wondering what I did wrong, and the conclusion is always nothing.
I've voted on similar issues and apparently the problem has been here since the arena's inception and there is still no good solution for it.
Now I know you can go to full control mode, but that's not a good enough solution, because you have to manually activate it, when the expected behavior is the game to give you a chance to REact, not the player having to PROactivaly forsee that the game won't let them get to the phases they expect and therefore have to manually account for it or be forever doomed to always play in full control mode, making games take at least wice as long and twice as demanding regarding concentration.

Now I'm left wondering if this is an incident with Ragost only, maybe some other cards that have static abilities granting activated ones to other permanents, as it's not an ability that the artifacts don't intrinsically have.

But the underlying problem here is that not all abilities and game states are considered when deciding to give a player priority or automatically go to the next game phase. Please do better coding on this. I'd rather have to wait out a timer for 100 games I have lethal beacuse my opponents are time wasting, even if the only thing they can do is to carck a treasure or something, than to lose to the game not giving me priority when I clearly have winning lines.

Left a Log taken after the game, no idea if it helps.