This is not a bug anyone is going to be able to investigate – the game in question (6902095) gives an internal error if one tries to load it – but I thought I'd report it anyway.
I used Procession on a 3-cost action card (I can't remember which one) and gained a Nomad Camp when that card was trashed. After doing so (and with both no Actions left and no Action cards in hand) I wasn't offered the option to autoplay the 3 Silvers that I had. Although I can't remember whether I tried playing them individually, I'm fairly sure that it wouldn't have been possible. I had a Night card (Ghost, I think) in hand. I was being asked which Night to play, which suggests that my Buy phase had been skipped completely.
Sorry for the vagueness of this report. I had expected to be able to go back and look at the game in more detail, e.g. to confirm that I hadn't somehow clicked on 'End buys' accidentally. Alas the internal error when trying to load the game precludes that.