Can you paste us the errors?
You can try the following :-
1.Go to Network settings and Change the Connection Properties from public to private as shown in Images.
2.Check the advanced settings of Windows Firewall > Click on inbound rules and check the permission is enabled or not for mendix native mobile.
This solution worked for me (the private connection ).
You can read more about troubleshooting here: https://docs.mendix.com/howto/mobile/common-issues