I am also having issues adding new devices to homekit. Running Eero and 16.1.1 iOS. I am able to add devices directly to their associated apps but anytime I go to add to homekit it just times out without adding. All iPhones/Ipads/MACs/AppleTVs are up to date. Note: After it times out and I try again, Homekit says it is already added... but it isn't there.