RX battery voltage not showing using Crossfire CRSF

[JamesHamilton4]

I'm using a Radiomaster Zorro, with Crossfire on a quad with Betaflight. I'm using the latest version of LuaTelemetry on the Zorro. On the Lua Telemetry script the RxBat battery voltage on the top right always shows 150, without a V symbol. I've tried re-discovering sensors. Lower down the "batt" reading shows the correct voltage of the 4S battery on the quad. So I don't what what 150 means or why RX Bat on the top right would differ from the reading lower down. All other values seem to work fine.