I got a 500 GB hard drive last year and put it in a hard drive case and released it on the network. When I'm in the same WLAN with my laptop, I get the hard drive connected to the desktop PC. However, when I go into my hotspot from my cell phone, I suddenly can't access the hard drive connected to the desktop PC.
Is there any way that you can connect a hard drive to your PC, connect it to a WLAN, and access this "hard drive" with a laptop from another WLAN (e.g. The WLAN hotspot from your cell phone).
I tried everything and it just doesn't work.
The solution is called VPN. Depending on which router you use (Fritzbox would be good, cable boxes and Telekoms Speedport can't do this), you can allow yourself a VPN entry point into your local network. If necessary, you can also do this with a Raspi.