Making sure the charging cable is inserted properly
Updated
Make sure that the audio jack is completely pushed into the device, otherwise, the device will not start charging
Make sure that there is nothing inside the audio socket preventing the plug to be inserted fully
You might need to use a small flat screwdriver or a tool with similar shape to remove any plastic residues there might be on top of the socket
Sometimes you might need to push the cable really hard to get it in as the angle of the socket might be a bit misaligned with the plastic hole
When inserted correctly, the plug has to make a clicking sound when pushed into the socket
It is possible to check if the device has detected that the cable is plugged in. In the Smart Shades app > Device Settings > Charger Connected Yes/No
Make sure that you have the latest firmware installed to see this option in the settings. See Checking for Firmware Updates.
Below are photos with fully inserted audio jacks. There are two different variants of the USB cable when comparing the sleeve length. You should check which version you have to see how long the gap between the outer side of the sleeve and the bottom of the device has to be.