Hello,
Here is what you can do,
Xibo for Android is capable of communicating over HTTPS, the only step required in most cases is to change the CMS URL in the client settings to be prefixed with https:// instead of http://
In some cases it may show as untrusted certificate then follow instructions here
If that doesn’t help, you probably need to update CA root certificate (I think you are using windows server right?)
in that case, you will find solution here.
Best Wishes,
Peter