Hello all,
I've got a Thingy 9.1. I've successfully built and flashed the serial_lte_modem example (with no changes) onto the device but when I open the serial port in LTE link monitor I get no response at all. I have reset, turned it off and on again, still nothing.

Unfortunately these instructions https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/applications/serial_lte_modem/doc/slm_description.html don't have any advice on what to do if I get no response.
I am programming over USB using nRF connect v3.6.0 programmer.
Thingy 9.1
PCA20035
1.0.0
2019. 43
When the asset tracker application is loaded, the serial port responds normally.
What have I done wrong?