Dns settings iptv

Hi I am not sure where to post this but I believe it is the best place.
Can anyone tell why I can not change the DNS settings on a android 9 or 10 box, it works on the previous versions but not on android 9 or 10 ? I tried a couple of different boxes and when I go into the box and try to change it to static and I input the IP address, Gateway, etc it all works and saves but when I change the DNS1 & DNS2 it lets you input your DNS setting but will not save them, once you go back in they default to the ones from Google that were there already ?
Any help would be much appreciated please

Thank you

google controls android