Hi,
If you check ASCII table, 0xA0 corresponds to ‘LF’, “0x0D” corresponds to ‘CR’ and “0x1A” corresponds to ‘SUB’.
Once you got “Please reboot your module…”, Did you reboot the module? After that also you are not able to update FW?
In that case I will suggest you to remove power supply of the module and put it back 
-Alex