Hotspot function connects but has "no internet"

I cannot get the hotspot function to work correctly on my Blue Life Mark handset.

The SIM works as a mobile hotspot in another phone and I also have another SIM in the second slot which does not work either, the other devices (e.g. laptop) will connect, but shows as"Connected, No internet"

The SIM card does not seem to be the problem, and I have tried various devices apart from just one laptop (tablets and iPad), all have the same issues, it seems to be the phone?

I don't want to have to root the phone as many apps I use won't work on a rooted device.

Any ideas?