Companion App - notifications iOS

I am using Home Assistant official app on my iPhone. And now that my HA is taking shape I wanted start playing with mobile phone notifications.

Yesterday after hours of trying, resetting, uninstalling I managed to get it working - I setup Frigate motion notifications and that also was working great.
Today however, when doing some more testing I removed and reinstalled the mobile app and now again I am stuck - the notify.mobile_app service is just not appearing in my HA.
I have followed the troubleshooting section from here:
Right now in the Notifications section in the mobile app it tells me that Local Push is Available, and in the Push ID: Not registered f…mote notifications. When I click rest as per the troubleshooting guide I get this error message (in the mobile app):

The operation couldn’t be completed. Failed to checkin before token registration - OK

Anyone has seen that error msg? How do I get around that problem?

Do you have anything that may be blocking Firebase’s ability to talk to Google servers? For example, a VPN or something like AdGuard.

Thank you - that was it - I am running AdGuard.