Toogle "Send notifications..." not saved/no notifications

Hi,

I am using Core Tunnel 3.10.9 (E801C) with a premium license from the Codin store, and I have a problem with setting up/getting notifications. I have several connections configured, but when accessing the "Settings" of each connection, theres (1) a problem trying to click on the "Connection" tab (I have to click several times on "Advanced" and then I can click on "Connection"), but (2) even if I select the "Send notifcation..." toggle and press save, it does not save and no notifications are sent.

Core Tunnel is enabled for notifiations in System Preferences.

Thank you for any tips!
Best regards