Hi Greg,
Interesting question!
What data source type are you using? I would consider trying a Serial data source with the catchall configuration described in posts like this one: https://forum.infiniteautomation.com/topic/2274/serial-data-source-trouble-to-show-value-from-com-port/2
One thing that would enable someone to do is drop a breakpoint in the SerialDataSourceRT's serial event method and see what is actually being returned to Mango: https://github.com/infiniteautomation/ma-modules-public/blob/main/Serial Data Source/src/com/infiniteautomation/serial/rt/SerialDataSourceRT.java#L250
If we didn't want to bother with breakpoints, we could log I/O from our serial data source and we'll either get an event, some characters captured and recorded in a log, or absolutely nothing. If we get an event, we'll need to troubleshoot what the event is for. If we get things captured and logged, we would need to figure out where the actual protocol you were attempting (or maybe it was a Serial data source all along!) is going astray. And, if there is nothing at all, then I would wonder if there's some subtlety in the Linux configuration of those ports that isn't comporting with the JSSC library's expectations. But, I would have expected an event when attempting to open the serial port, if that was the case.
I assume you updated the regex in the env.properties for serial ports to correctly resolve these ports. Sounds like you got past that part.