Most of the time, the "OK Google" feature of Google Assistant works fine. I say "OK Google" and it goes into listen mode. However, everytime I finish a phone call, my phone no longer goes into listen mode when I say, "OK Google". Doesn't matter whether it's immediately after the call or half an hour later, it basically just ignores me completely.
Rebooting the phone is the only solution I've found that fixes it. I am currently on Android 7, but I believe this was an issue on Android 6 as well. I have a Galaxy S7.
Is there something else apart from rebooting I can do to stop this from happening?