Problems with RN2903 and class c

Hello everyone!
I’ve problems with some RN2903 modules, the situation is as follows:
I update the firmware that has the RN2903 by default version 1.0.3, I update it to version 1.0.5 which allows working in class c, in this way I can have ascending and descending data in the module, but some modules receive badly the data issued by the LoRaServer.
Someone who can help me please with this problem.
In the Microchip forum I have not found anything related to the topic.

hey, can you change frequency plan for this module? helpme to change to as923