The answer is to your question is that the RocketHub should work just fine in your truck.
One of the issues with power inverters is the "quality" of the power they produce. It may seem surprising that the 120 volts "AC" produced by inverters varies in quality. However, this is true and the result of the internal circuitry and design of the inverter. I could go into technical details here, but it would be hugely confusing. Also, different electrical and electronic devices are more or less sensitive to the quality of the AC.
A toaster, for example, has very different requirements from a microwave oven.
You might try a different, perhaps more powerful or higher quality inverter and see if that works. You could also unplug all other devices from the inverter and plug in just the RocketHub to see if it will work that way. The quality of the AC power coming from the inverter may decrease as the load on it increases. Add up the total power being drawn from the inverter and check to see how close you are to the capacity of the device.
I have a suggestion which may seem silly, but will at least demonstrate if the 'Hub works when physically located in the truck. Just as a test, (although an exercise which may end up mystifying and annoying you) park the truck, runnning, close enough to the shop, your home, or whatever, and run a long extension cord from the building into the cab of the truck. Plug in the RocketHub and check if it works when supplied with clean, power utility-quality AC. Ensure that the AC inverter is turned off when doing this test. This will also tell you if there is some interference inside the truck such as from the CB, the truck's computer/electronics, microwave oven, etc. Although I assume your regular cell phone works inside the cab.
If the 'Hub works inside the cab when connected to standard AC power, you at least have a place to start.
Also, you need to remember that the cab of the truck is made of metal which will shield the 'Hub from radio frequencies, but also contain them inside if other equipment generates electrical/radio "noise". I should point out too that AC inverters, due to their design, can generate lots of radio interference as well.
Another place to post your question is with the Ericssen W35 Forum:
The manufacturer may have suggestions, as I know from the Ericssen Forum that they have customers using the W35 on board ships. I did a quick check and Ericssen does not seem to supply a 12 or 24 volt DC power option for the W35.