The CPE has a directional antenna, while most hotspots use omnidirectional antennas. Basically, this means that if the hotspot's radio signal is too weak to establish a stable WiFi connection with client devices, it most often can't feed a CPE, too. In such a case a second CPE would be needed on the hotspot's side to establish a stable link.

But since the CPE's receiver sensitivity is usually better than that of client devices, there is a change (albeit a small one) that it could work with only one CPE. You should first try to get a WiFi signal of one of the RV park's hotspots with the CPE in client mode. If this succeeds, you could set up the rest. So, set client mode, do a survey on the CPE, connect and lock it to the nearest hotspot you see in the survey and try to ping the hotspot with the built-in diagnostics tools of the CPE. If this works, you could change settings to improve the signal. But if you don't even see the RV park's hotspot in the survey, all bets are off. It's the omni antenna of the hotspot which is critical here, not the CPE's antenna.