Wireless Joint

For easy build always like the the Quectel EM12.

Sorry, wish I'd have seen this post earlier. Yes all providers block incoming traffic. Your on the right track though, I have a pi3 setup with reverse tunnel to get in from the outside. I have mine setup to forward to a vultr server as my middle man. Might check out ngrok.com, seen a post here about ...

Typically the issue is in the main settings. You have to set it up with the APN manually set to vsblinternet (I know there is an auto visible option, but no no!) Then make sure the APN is set to IPV4V6 type. None for Authentication type. blank for password, etc.

Also set it to No roaming, 4G only ...

Currently pretty much all phone plans have some kind of hotspot limit.
If you don't want to get a full blown router to bypass the limit, you could go with an inexpensive GL-Inet MT300N mini travel router smaller than a pack of cigarettes.
https://www.amazon.com/GL-iNET-GL-MT300N-V2-Repeater-300Mbps ...

Bandlocking is done via AT commands:

I copied this from a previous past and stored it as I use it on my EP06-A but I believe the commands are the same for all quectel based modems:

Enter the following AT commands, and write down your original band values before changing anything.

AT+QNWINFO ...

Can you provide traceroutes through CyberGhost with Verizon and Visible. Comparison might yield some info on whether Visible is blacklisting/throttling public VPNs or if it is just very slow transit between Visible and Cyberghost.

Do you have access to a personal/private VPN or maybe a work related ...