Is Manual Control broken recently?


I have all my SRTs set to 30 minutes when manually controlled. But recently it doesn't stop after 30 minutes.

About 9.20 this morning I set one to 20 manually on the SRT but it was still going until right now. Tado was reporting the room at 20.3 degrees.

What is the expected behaviour if the room doesn't reach the requested temp in 30 minutes. I was kind of hoping it would stop heating rather than keep trying to reach it (potentially for hours!) Manual control to me is to quickly boost the room rather than permanent heat.