Your HomeRunner site can stop syncing with Guesty even when nothing on the website has changed.
Why this happens. Guesty limits each API client to 5 access-token issuances per day, counted on a rolling 24-hour window. If the API client HomeRunner uses is shared with other tools or dashboards, their combined usage can use up that daily allowance. Once the limit is reached, Guesty refuses new tokens for every consumer using that client, and syncing halts until the window frees up.
What you can do. Create a dedicated API client in Guesty that only HomeRunner uses.