I'm encountering a strange behavior with one of my home's on Home app while I'm off network. When I launch the app it indicates that the hub is not responding and all of my devices are unavailable. However, on the menu bar at the bottom if I switch to "Automation" and back to "Home" the pop-up goes away and my devices are accessible again (sometimes this take a few attempts). Siri is also able to consistently control my devices without an issue. The same behavior occurs with Home app on other devices (e.g. Mac) and with other members that have access to the household. 3rd party HomeKit app like "Controller" does not have an issue.
This issue began with iOS 26 and I haven't had much luck resolving the issue. I already tried rebooting everything, including removing and re-adding an Apple TV (home hub). I have other homes shared with me in Home App with similar network/environment that are still working. The home I'm having issues has the most number of devices though (over 100+).