Cyano seems to proliferate in low nitrate tanks. (In my experience) I’m going through the same thing at the moment. I routed a tube into a filter sock in my sump then just sucked up all the cyano. So just raise the nitrate, stop dosing aminos and feed less. You could also use chemiclean which is 100% effective but I’ve had rtn from it.
Idk if it's cyano then, my nitrates are like 15 now. My goniopora just keep getting this slimy algae that looks like cyano and it's causing them to have stn