Probaby is correct. If a TV SPLITTER Transformer is being used it will read a short...
Normally the WALL PLATE has the cable TV coming in and it is sent to the main TV connector on the front of the wall plate and the bedroom TV jack. Then when you push in the small button on the wall plate this inhibits the signal coming in from the cable TV connections and connects the OTA antenna to the main TV connection and the bedroom connection. It also send up +12VDC only up to the BATWING wing antenna to power up the boost amplifier. It does not send +12VDC to your main TV or bedroom connection...
The antenna wall plate is just a smart switcher unit. There is no boost amplifier inside it... Having said that most everybody calls this the Booster panel haha
When I am at home working on it I always use a 50-foot extension cable from my house cable TV and run that out to the trailer. Then I can try all of the combinations to get them working correctly...
Checking for ohms with TV cables not a good working effort... Need to check them with TV signals instead. Sounds likes it working ok since you said you had fed TV signals to both TV's already...
Roy Ken