Push notifications (mobile message) & timeline notifications are unreliable since they can get rate limited without any warning whatsoever.
They also have no, or very limited historical data, without filtering possibilities.
Rate limits can be removed by either wait for 24h, or restart Homey.
These rate limits are caused by too many notifications in a certain amount of time, until this day I don’t discovered the actual values.
That said, many other (free) message services can get rate limited as well, but usually you’ll get notified.
I’ve good experiences with both the CallMeBot app services Signal and Telegram.
There’s many other available services, search the app store for