Thank you for posting this. There are many changes between those versions, but there one that really sticks out. The JSerialComm USB-Serial driver was updated from version 2.6.2 to 2.7.0.
@N_ALSCAN, I wonder if this could be related to the issue you are having? Would you please try version 11-24_2226 and see if that will connect for you? There is also a new version 12-12_0606 available that has the older version of the serial driver. Otherwise, it is the latest firmware/software.
@N_ALSCAN, re-reading your post, I noticed that you are referring to BTConfig software (vs BTCFG-II software). That would explain the issue you are having. The P25RX software will not detect a P25RX-II device. There is a separate page for the P25RX-II software here:
https://bluetailtechnologies.com/pages/p25rx-ii You can verify which model the software is for. When the BTCFG/BTConfig software starts you will see either a bold P25RX or P25RX-II next to the Bluetail Technologies logo depending on the model it will work with.
edit: I made some changes to the web site to make it easier to find the correct software/firmware for both receiver models.