I tried to update some of my M8T modules to the latest firmware (3.01) but had to learn that the update is only available for the M8N and M8P.
Hence, my question is, which firmware is running on your M8T GPS modules?
The firmware present in our devices is TIM 1.10. The update with M8N firmware has been attempted by some users and is functional, although it breaks some functionalities.
Firmware TIM 1.11 has not yet been made available publicly and is only for testing purposes.