Google My Business accounts may be occasionally disconnected from your Circleboom Publish account, and you will need to reconnect your account in these instances. As put on Google's developer page, it can occur due to several reasons:
You may have revoked your app's access.
The refresh token has not been used for six months.
You changed passwords and the refresh token contains Gmail scopes.
Your account has exceeded a maximum number of granted (live) refresh tokens.
You belong to a Google Cloud Platform organization that has session control policies in effect.