I am struggling to get Hold to work correctly. Generally all my zones are set to Auto - and have an associated and active profile. If I want to boost the heating for an hour I go into the app - select the zone that I want to boost - I then go to hold - and select a time and a temperature. The heating then switches on and the hold period begins with the flame symbol appearing. If I then go to Home in order to view all my zones - the flame symbol appears for a few seconds then switches off. If I then go back into the selected zone - the temperature has reverted to the pre-hold temperature. Am I doing something wrong? All I want to do is boost the heating for an hour.