Hello
Look at this thread for your disconnect issue. Yes, it’s expected, it doesn’t fully work out of the box, but mention your problems, provide enough details and maybe you can get some help.
My Librem 5 is often hot, I have to put it into my chest freezer sometimes, I can’t send MMS, receiving MMS isn’t straightforward as I have to switch to another Access Point Name, SMS don’t work reliably, I have some echo on calls, Internet doesn’t work when the modem seems to sleep, Phosh just crashes sometimes, I have to retry many times to mount it as a USB storage device, etc.