I'm having the same issue on my bot account with the "Download of player inventory failed." And sure enough, I can't access the account on my mobile devices either (I get the "Failed to get game data from the server." message with the purple "Retry" button. Meanwhile, my non-bot account is able to log in fine from my mobile devices. Thus I'm also worried that this is a ban that is related to botting, but I don't know.
If it helps, here's some more information. I typically run the bot from 2 locations (but not at the same time): my home (while I'm home) and work (while I'm at work). I don't use a VPN. My home and work are 2 blocks away from each other, and my coordinates for the bot are right here in my downtown between my office and work (I happen to be in a location that is relatively dense with players and pokestops). The bot was basically walking in a circle that encompasses my house and my work. The bot was running fine when I turned it off and left work for the evening. An hour later, I tried to start it from home, and that's when I got the errors. So I wasn't transferring or renaming or even online when I got banned, as far as I can tell.
Anyways, I hope it gets fixed soon.