Field map of an IOS device can connect but Android is not connecting

[gisbd]

I have an ArcGIS Enterprise system version 11.2 deployed, and it has been tested successfully from an iOS device where Field Maps is connecting. However, when the GIS team tries to connect from their Android phones, it is not connecting and displays an error message that says, 'The server you are trying to connect to is using an untrusted certificate.' How can I resolve this issue?

[CodyPatterson]

Hey @gisbd 

On the ArcGIS Portal server, is the Web Server/Web Connector using a CA signed certificate, also if you navigate to your ArcGIS Portal site on the web, does it have a trusted certificate?

I am also using 11.2, and when I had a domain or self-signed certificate, I was unable to connect.

Cody

[gisbd]

Thank you for your reply,

I am using Let's Encrypts free SSL certificate.