Certificate Error - Same sites every day.

Hi!

I´m facing an issue that I could not resolve. 

I have and XG330 with SFOS 19.0.1 MR-1-Build365. 

I use the firewall as a web proxy. Microsoft domain services enviroment.

It´s weird that it´s working any webpage without any problem and suddenly, the whole google suit stop working. Sometimes, bank sites like https://www.bancociudad.com.ar

When the user tries to access, the tipical error shows up:

"NET::ERR_CERT_AUTHORITY_INVALID"

So, I deployed the Appliance Certificate to the clients. But it didnt work.

The issue resolves itself after 30 minutes, more or less. I mean, I do not touch nothing and suddenly, all start working again without problem.

Today, I look for the certificate and it´s not my appliance certificate:

I dont know this certificate.

Here is the Rule in one of my networks:

I also manage an UTM SG330 in a different enviroment and I do not have this weird behavior

Some advices? Any help?

Thanks