Help Another "OK Google" question

[markdoc]

I have had problems with "OK Google" in the past but fixed them. Recently I've developed a problem that's a little strange. Every few months, "OK Google" stops working and none of the old fixes work. What does work is restarting my phone in safe mode. I wait a few minutes then reboot normally and "OK Google" works again for few months. Because it stops but works in safe mode, I would think it's an app. But what app would behave for a while then stop"OK Google", then behave again, etc, etc, etc? Any ideas are welcome. Thank you in advance,
markdoc