There are two different things going on here. One is that when Indigo queries a sensor value from a module it doesn't try to specify which specific sub-sensor (in this case LUX or TEMP) it wants. This is because lots of modules don't reliably support this type of querying and return unexpected or unpredictable results. Therefore, Indigo just sends a more generic query and the module responds with whatever it thinks it is appropriate (if I were the Fibaro engineers I would have returned TEMP over LUX, but that is their decision).
But that only impacts when Indigo sends a query to the module. For FGMS001 that is only during sync (which it is awake), so we can just ignore the fact that LUX is returned instead of TEMP at that point as a minor inconvenience.
The real problem here is that your modules are not broadcasting out temperature reports it sounds like. It should do that based on the configuration parameters for Temperature Sensitivity, Temperature Measuring Interval, and Temperature Reporting Interval. Based on your Event Log those configuration parameters look good to me and it sounds like you've tried tweaking those settings, so I'm not sure why the module isn't periodically broadcasting out temperature changes. There are other reports of this exact same problem. It sounds like in those cases the user eventually got it to work reasonably (but not ideally) well.