I was just having the same issues. Hopefully its a bug and not a forever decision. Not everyone has more then one device to play on
Same. I can't imagine they would remove that ability intentionally. I've got multiple accounts I've dropped quite a bit of money on. Removing the ability to access those would be ethically questionable at best, legally questionable at worst.
I was just having that same issue as I made and use 3 fairly decent sized accounts and just found the log in with Google button missing which is what I always used to switch back and forth. I did figure out a way around that though. Instead of the Google button, click the log in with Kabam button and enter your credentials there. I'm guessing you have to have linked your accounts (google to kabam) for this to work though. Good luck!