Tuya motion sensor is not supported in Home Assistant

I’m trying to use this for some toilet occupancy sensors (thanks Covid) in our bar. the sensors work great and the ping sensor is accurate, however I can only get one of the sensor templates to work reliably ,the other one seems to just flick between on/off constantly. I wonder if I have to define the two sensors differently?

sensor:
  - platform: time_date
    display_options:
      - 'date_time'

input_number:
  motion_sensor_idle_secs:
    name: Motion Sensor Idle Seconds
    initial: 130
    min: 10
    max: 3600
    step: 1

binary_sensor:
  - platform: ping
    host: 192.168.2.62
    count: 1
    scan_interval: 1
    name: ping_tuya_motion_sensor_gents_toilet
  - platform: template
    sensors:
      ping_tuya_motion_sensor_gents_toilet:
        friendly_name: "Gents Toilet Motion Sensor Alarm"
        value_template: >-
          {{ as_timestamp(states.sensor.date_time.last_changed) - as_timestamp(states.binary_sensor.ping_tuya_motion_sensor_gents_toilet.last_changed) < states('input_number.motion_sensor_idle_secs')|int }}

  - platform: ping
    host: 192.168.2.61
    count: 1
    scan_interval: 1
    name: ping_tuya_motion_sensor_ladies_toilet
  - platform: template
    sensors:
      tuya_motion_sensor_ladies_toilet:
        friendly_name: "Ladies Toilet Motion Sensor Alarm"
        value_template: >-
          {{ as_timestamp(states.sensor.date_time.last_changed) - as_timestamp(states.binary_sensor.ping_tuya_motion_sensor_ladies_toilet.last_changed) < states('input_number.motion_sensor_idle_secs')|int }}