Demo server has forgotten my registered device twice

Twice during the time I've had my device in my car and registered to demo.traccar.org, my device has been erased from the server and I've had to re-add it. Why does this keep happening?

We clear demo servers periodically because there are too many users/devices and finite server resources.

Is there a server available for those of us who are hobbyists and not power users where our devices might be able to stay?

Yes, of course there is:

https://www.traccar.org/product/tracking-account/

or

https://www.traccar.org/product/tracking-server/