Hello @Ptset,
Can you post a simple sketch of how you have your network setup?
If you have a network switch in between your Pepwave Surf & the WAP, and if you are running VLANs, you need to have a switch that can handle VLANs. Most consumer switches are unable to do this and they will cause issues with VLAN tagged traffic.
If you do have a switch, you may find some of this other recent forum thread useful VLAN Setup on Managed Pepwaves - #5 by mldowling or it may open up more questions too.
Others here in the forum will look at this and if you have an image of your network it will assist them in guiding you.
Happy to Help,
Marcus 