ONE R - external mic does not work

With my INSTA360 ONE R I would like to use an external microphone. I have the original INSTA360 microphone adapter, but no matter which external microphone I connect to it (Rhode Video Mic, DJI Wireless), the audio level of the external source is displayed on the screen, but only the internal microphone is recorded.

Does any one know, what could be the reason for this?

Thamk you in advance.