Hi Ezra! 

I suspect the issue might lay somewhere between your minimum entrant and max entrants. I have my minimum entrants set at 0 and my max set at 2000. You can check out the shows and see how many entries are in them by going to Explore > Shows Arena. Then you can filter by discipline and level. I see that a lot of the driving shows are currently at 800+ entries. I do see a few shows that have 2 entries right now but those could be recent entries which would explain why they weren't being entered if you were trying it earlier in the day. Can you try widening your parameters a bit more and see if that helps at all?

I changed the parameters to 0-3000 and it entered Bianca into almost the rest of her available shows except for one. Upped the settings to 0-5000 and it did not enter her into that last one. Manually entered her. Went to the next horse who had 1 show entered already and entered her in the rest of the shows via Enter All and it worked for the next horse too. So problem fixed aside from that but with the first one. Might have been something on my end though. Thanks for the help!