How do I turn off AP Fastboot Flash Mode?

[Stu Smither Wulsin]

Hi. I have a Moto G4 that came with the Amazon Prime ads. I tried to install an apk to get rid of them, but it didn't work. No problem. Except now my phone is always starts up with the AP Fastboot Flash Mode (Secure). I don't mind except that it is preventing me from installing the newest Android update. I tried doing a factory reset and it didn't help. Any advice? Shouldn't there be an easy way to go back to the default boot loader?

Thanks!