Same issue, when I animated [[Kylox's Voltstrider]] using [[Case of the Filched Falcon]], it would put the trigger on the stack, but it would only let me resolve it. I didn't choose a spell or get to cast one from exile. However, when i crewed the already-animated voltstrider, it DID let me cast a spell. I really want this to be fixed

I had the same issue as well, which ended with me losing the game because of that.

I attacked with it, no prompt showing to let me cast a spell exiled with it (in this case, suspicious detonation). According to the 17lands logs, the spell was exiled to use the "crew ability" but then wasn't even considered to be exiled to the vehicle for some reason.

Just had this issue come up in a premier draft. Lost a game I would have likely won while I had 2 losses b/c of this exact issue.

In the screen shot there is a torch the witness exiled under the vehicle, but it never prompted me to try to cast it.

I had the same issue in premier draft. Attaching the log.

I also had this issue, during a Karlov Premier Draft game. Prevented me from using the instants/sorceries as intended, affecting the outcome of the game.

I had this issue as well. Sometimes I'm given the option to cast spells and sometimes I am not, and I can't figure out a rhyme or reason to why - I always have mana open to be able to cast the intended spell. When I get the "resolve" button screen, I couldn't see how to cast the spells exiled with Voltstrider even when I try to click on them instead of clicking the resolve button.

I too had this issue in my sealed event which cost a loss. I had mana available, the cards exiled had not been cast using this ability before, and I was never given the option to cast the spells. After reading the comments it does appear to be visual because the interface was prompting strangely.

Kylox's Voltstrider ability only lets me cast a card from exile when I have gathered evidence to make it an artifact creature. Not when I use a creature to crew it. Reading the card, this does not seem to be the intention. In a draft (that I payed for and was very excited to use this Mythic rare card in that setting) that I built my deck around this card. It has significantly affected my ability to win games. I know this bug won't be fixed by the time I finish my draft matches, but I am disappointed, because I had to spend gems to draft.

It's user error after all! Somehow i thought you could cast the cards without paying it's manacost. So the times it didn't work i had no mana open to cast one of the cards exiled.

At least I learned!

Edit:
Apparently it's not. I tested crewing both manners against Sparky and both times i could not select a card to cast.

Edit #2:
So i cracked the case! It's still a bug but it's a visual one. So sometimes the prompt only askes if you would like to resolve the ability. If you click resolve nothing happens. You can work arround this by not clicking on resolve but clicking on the cards exiled with the Voltstrider. Then you see all the cards exiled en you can click on the one you want to cast. Next you need the mana and you can cast the selected spell. My best experience is when using full control during the complete attack fase.

It's not how it's supposed to work but at least you can now play with the card without loosing value.

I had this same issue in a sealed event and it impacted my game play. See file attached.