Mac mini M1 & Apple Remote Desktop - cannot control it

I have a new M1 Mac Mini, set up to be Apple Remote Desktop controlled from my other devices. The Mini is connected to a LG5k display.

I from a remote device (say, a Macbook), I can connect to this Mac Mini via ARD. However, on the remote device the ARD screen is completely black. I can see the cursor, though.

I can move the cursor on the remote machine but it does not move on the Mac Mini. On the other hand, if I move it on the Mac Mini, it does move on the remote ARD display.

Both devices run Big Sur and I had tried connecting to Mac Mini from multiple other devices via ARD; result is the same, black screen on the ARD controlling device.

This used to work fine when I was controlling my old 2009 iMac and works fine when controlling an old 2011 Mac Mini. So it is something to do with the new M1 Mac Mini.

Any clues?