Connection problems

Hi,

I’m having issues connecting to my Home Assistant instance through Nabu Casa using the Android app.
When trying to log in remotely, I receive a timeout error during the authentication process.
Details from the app:
Error: net::ERR_TIMED_OUT
Status code: -8
DNS resolution succeeds
Port 443 is reachable
TLS certificate check fails
Server connection fails afterward
Home Assistant verification is skipped because the previous check failed
Important detail: I can still access Home Assistant locally without any issues using:
http://homeassistant.local:8123
So the Home Assistant instance itself appears to be running correctly, and the issue seems specifically related to the Nabu Casa remote connection.
I already tried:
Restarting the app
Retrying the connection
Checking internet connectivity
Has anyone experienced this before or knows what could cause the TLS certificate failure with Nabu Casa?

Or better, what should I do to get rid of this problem.

Did you set up the external URL in the mobile app settings?

Im using the homeassistant cloud as home assistant Url

I need to mention that is works one day, and the other it doesnt.