Forced to have different firmware on HM-ES-TX-WM

Together with openHAB I have a CCU2 with about 100 devices. Two of them are HM-ES-TX-WM, one with firmware 1.2 and one with 2.5.
Firmware 1.2 has a ferraris sensor connected to the device, firmware 2.5 has an ES-IEC connected.
I cannot have the same firmware version on both devices as each sensor only works with the appropriate firmware.

As a result I don’t get data from the 1.2 device. The log file shows
[ternal.handler.HomematicThingHandler] - Channel not found for datapoint
[ternal.handler.HomematicThingHandler] - Channel not found for datapoint

I have also read the information in the log file that same devices should have same firmware versions. But as stated before I have no choice in this case.
Any idea how to receive values from the 1.2 device?

Hey, since last weekend I have exactly the same problem. Installed the two energy sensors, also with the need to use the two different firmware versions… and errors in the log. Did you find anything helpful in the meanwhile?