Problem to logon on Android devices

Hi all, it’s my first post.
So, i have problem with android app.
when I try to log in to the server I receive a message like in the picture (Invalid URL or unable to establish a secure connection…), iOS works normally, there is no problem on computers apps and by the web, file transfer works.
It is possible to connect after removing the port :3000, pressing Connect, after request with a fault, adding the port :3000 again allows you to log in. The problem occour again after killing the application task in android system.

found solution in here

just join certificate with intermediate cert to one file…

Hi Itasp,

Can you explain a little better ?
what is the intermediate cert ?

My server is auto signed

Thank you

You have to copy the contents of the intermediate certificate file and paste it into the file below the contents of the root certificate. (merge their key content)
about certificates here