Evohome and shelly Door

Hello,

I am not getting my programming that I want in order. Could someone please tell me what I am doing wrong?
Situation: I have 3 students in my house and on each room I placed a radiator knob from evohome. I have placed Shelly window/door contacts on the windows. The idea was, when one of the students opened their window, the evohome radiator knob went to 6 degrees. I was able to create this in home assistant. I made a second automation when they close the window again that then the evohome radiator knob goes back to running the normal program. These two commands work perfectly.

Now I run into another problem, as they are students ;-). If the window is open and the radiator goes to 6% and the student manually turns the radiator knob to 22 degrees, the heating starts working again even though the window is open. I had been trying to make an automation that for example, checks every 15 minutes if the window is still open, and otherwise turns the radiator knob down to 6% degrees anyway. But this apparently doesn’t work, I must be doing something wrong.
Thanks in advance for the help. (I used google translate to compile the text, my apologies for errors)

alias: Studio Badkamer Raam open 6 graden
description: ""
triggers:
  - type: opened
    device_id: c76d65a3540902e29827634baee4abbc
    entity_id: 8df0528a77b3b83f00d36dd555a7d3d2
    domain: binary_sensor
    trigger: device
conditions: []
actions:
  - action: evohome.set_zone_override
    data:
      entity_id: climate.studio_badka
      setpoint: 6
  - repeat:
      sequence:
        - delay:
            hours: 0
            minutes: 5
            seconds: 0
            milliseconds: 0
      while:
        - type: is_open
          condition: device
          device_id: c76d65a3540902e29827634baee4abbc
          entity_id: 8df0528a77b3b83f00d36dd555a7d3d2
          domain: binary_sensor
mode: single
```