Trv’s not following their schedules

Hello
Hoping to get some advice. This evening 1 of my trvs did not follow the set schedule. The room was supposed to start heating to 20deg at 18:00 hours - 19:00 hours from a previous temperature of 14 deg. The trv never opened. The graph showing the room history did not show the requested change at 18:00. When I noticed and manually changed the temperature at 19:10 the trv called for heat and the radiator became hot.
One of my other trvs had a delay of 14 minutes before following the schedule.

Any advice would be welcomed.

Thanks