Not able to bring ad-hoc connection up

I am trying to set up an ad-hoc connection with another linux system on my ubuntu 20.04 laptop. I have managed to do this yesterday but for some reason I am not able to do it now.

I have followed the command line instructions from here:
WifiDocs/Adhoc

But when i try to bring the interface back up with

sudo ip link set wlp1s0 up

I get

RTNETLINK answers: Device or resource busy

I’ve looked at every discussion I could find, most suggest to stop network-manager, which I did following the wiki, so it does not solve the problem.

dsmeg -w does not show any error.