Networks dropping from Max Transit

We use a Pepwave MAx Transit Duo in an RV and I have noticed at times the 2.4Ghz and 5.0Ghz networks supported by the router do not always fully show to some or all devices. A Pepwave reboot usually fixes this but then they can drop again. On my PC it tends to drop more where the PC drops WIFI connection and when I check for any of the Pepwave neworks on a different device I may see them or may not. I have 4 WiFi APs and often only one can be seen inside the RV.

Any thoughts on troubleshooting?