I encountered the exact same issue with two remotes where specifically ch1 left on instant mode won’t work but seemingly got it resolved by re-pairing one of them as a matter device.
This trigger simply never triggers for some reason.
event_type: state_changed
event_data:
entity_id: '{{ var_scroll_left_ext_ch1 }}'
trigger: event
id: scroll_left_ext_ch1
The device itself shows both the events and button sensors working fine
Looked into it deeper and found the silly culprit.
var_scroll_left_ext_ch1: |-
sensor.scroll_wheel_living_room_current_switch_position_2
sensor.scroll_wheel_living_room_battery_type_2
Using the Battery Notes integration creates a battery type sensor that is picked up by your regex for switch position 2.