debian 9 – Problems ISPconfig3 and Ec2 in AWS

I am setting up an infrastructure in AWS in which I am using the ISPconfig panel to be able to manage each instance more easily:

Last Thursday I hired an instance t2.micro installed the complete server along with the panel ISPconfig3.1.13 (the latest current version) and it goes like the perfect silk in every way.

However last Monday I hired a t2.small instance (basically twice the machine) I installed everything exactly the same as in the micro and when I spend a few minutes without using the panel leaving it open in the browser the menu links start to take me to https: //example.com:puerto/# until I reload the web in which I get the acceptance of the self signed cetificate.

I have tried to reinstall the panel, reinstall the certificate and even reinstall the full server; but nothing remains the same.

Has this happened to someone?