$40 wifi solution for your Airstream
Well, let explain the issue: All those internet hungry devices in your trailer need to be configured for the correct hotspot. These can include your Smart TV, Amazon Firestick or Alexa, a YoLink temperature sensor, Blink Camera, iPad...perhaps that Cerbo GX you had installed from Victron.
As time goes on, newer rigs will be full of iOT devices...like it or not.
It could be a pain. I use this:
TP Link AC750, $40 device. (TL-WR902AC)
It's a wifi to wifi router. Not a repeater. So, your internal wifi devices connect to its 'output' wifi signal persistently. (Technically, handed an internal IP with the gateway, DNS and router info)
Then it's 'input' wifi is pointed at your internet source. This could be the wifi at your home, your storage shed, mooch-docking, harvests host, boondockers welcome host or your cell phone when used as a hot spot.
It's not necessary if you have a star link or other cellular or satellite router and you are always connected via that source.