I flashed a new image to an older pi 2B that I used to use with astroprint 2 years ago. I can connect to the pi 2B when i connect it via ethernet to wifi router and desktop astroprint app, but when I try to connect via the edimax wifi dongle it will not show an astroprint.xxxx wifi connection to setup the pi 2B. I connected the edimax wifi usb dongle and it works when connected to my desktop to the internet. I tried 2 seperate pi 2Bs and flashed the astroprint image to sd card twice with the same results.
In order to emit a hotspot we need two dongles. Our own driver to allow simultaneous WiFi and hotspot connection got too old to maintain. You can setup your device as explained here: https://astroprint.zendesk.com/hc/en-us/articles/360000337286-How-do-I-setup-AstroBox-Gateway-without-dongle-hotspot-