How to connect MQTT authorized with Owntracks

using

logins:
  - username: [username]
    password: [password]
customize:
  active: false
  folder: mosquitto
certfile: fullchain.pem
keyfile: privkey.pem
require_certificate: false

connects to Owntracks (Mobile/iOS) perfectly. However, revisiting the Mqtt config after its recent update to 6.0.1, made me wonder why I hadn’t used require_certificate: true before, to make communication more secure.
Editing that field to true still connects to all subscribing clients, including Mqtt explorer. With the exception of Owntracks.

It says the connection is ‘Inactive’. I am not even sure that is not alright, and indicating a non updating period between 2 connects (it briefly shows connecting every now and then)

please have a look? thanks!