Animation of input_boolean workins in Chrome but not Safari?

Configuration Frontend
1

I have hmi coded as:

entities:
  - entity: input_number.sprinkler1_time
    name: Timer 1
  - entity: input_boolean.sprinkler_1
    hold_action:
      action: call-service
      service: mqtt.publish
      service_data:
        payload: 1
        topic: /os/gadget/12678832/1/0
    icon: 'mdi:sprinkler'
    icon_height: 24px
    name: Sprinkler 1
    show_icon: true
    show_name: true
    tap_action:
      action: call-service
      service: script.1595033396620
    type: button
title: Instant on/timed off
type: entities

The tap_action works fine on chrome on my PC with:

clicked

The hold_action also with:

held

When the front end is opened on Safari, everything else seems to work fine except for the input_boolean behaviour. Toggle switches, used in other places, to turn automations on/off, work fine etc. That is, the behaviour above is on Chome on PC but it is not seen on Safari on iOS.

Note also no tap_action or hold_action events are raised when the Safari browser is used, that is it’s not just a problem with animation of the HMI.

Is there a browser blocking mode stopping this HMI element in Safari?