I’ve never used a non Tesla charger until this week. At this hotel my car remains on after charging complete and drains down about 1 mile of range per hour then charges up full again after a few hours. It’s been doing this for two days.
There are several settings that can cause to car to not sleep. Sentry modes immediately comes to mind but search the forums for many posts about this.
Do you have schedule charging on at home? I think if you have schedule charging at home, it won't charge back until the next day's schedule charging time. But Schedule charging is disabled when you are away from home. So it is probably normal to charge your car back up when it started using up the battery.