I had zero actions, and had an offer from my friend to clear my porch of Neath-snow. I clicked Accept, figuring it would either cost me no actions or instead tell me I don’t have actions. Instead, it took away one action, leaving me at -1 actions, and didn’t actually complete the offer of snow-clearing, but did cause the option to remove itself from my list. Refreshing fixed all of these, but the bug was repeatable. Letting my actions refill without refreshing caused it to go to one action, as would be normal for an action count of zero.
Thank you, somehow I missed that, wherever it was posted.