My Huawei modem works in my PC or Laptop but not in my Solo - what might cause that?

While there are a few ways this might occur, such as IP conflict, the newest sims seem to introduce a new way this occurs. The sims default to IPv6 which the Solo units do not yet support.

This can be resolved by placing the modem in a laptop or desktop, accessing the modem's user interface, and creating a new "Profile" for the sim which uses IPv4 instead.

Here is an example from the Huawei user interface of a new profile set with IPv4 as the default instead: