Some time ago, I was able to access and control my Hubitat devices when I was away from home. However, since I upgraded to the latest Hubitat version, I can no longer do that.
Do I need to configure something specific to enable remote access again?
Also, is there any way to get remote access for free, or is it now only available through a subscription?
Remote access to control your devices via Mobile app or dashboards is free and doesn't require any special set-up, or subscription. Just make sure that the hub can connect to the cloud, and that nothing on your local network is preventing hub's access to the internet.
Is just that one tile not reporting status properly, or can you not access anything when away (any dashboards in the app's Dashboard tab or any devices in the Devices tab)?
Based on that tile's name in your screenshot, it looks like your using a community-developed dashboard builder, so I'd verify that is set up correctly before assuming a wider problem with the app itself.
Since that tile tool is a community-developed app, you will likely get the best answer/support by posting details of this issue in the thread created by the developer for that app.