Device adoption failed because the device does not respond to adopt commands. this is the eroor i am getting

i have installed omada controller on TRUE nAS scale , i am not able to adopt any of the devices on my network , version is 6.2.0.17, but i am able to adopt all the devices without any problem on OC...

@Vincent-TP i too face very slow user intferface , i am using oc200 v.1.0. when will this issus ebe rectified