Error with Data Refresh and Gateway Configuration After Publishing PBIX File to Power BI Service

I have connections to local drives and a database. The database connection is the one failing since 2 weeks or so. Before that, I could sing in without problem, in the configure menu of the semantic model, inside the data source credential section. 

In the connections manage connections and gateways menu, I can see that all my connections are:
Type: File
Gateway cluster name:  nicolas.mosquera-rey (Personal mode)

Except for the database connection which is failing: 
Type: MySQL
Gateway cluster name: - 

I also updated the personal data gateaway, but it's not working still. 

This is the error message:

Failed to update data source credentials: An error happened while reading data from the provider: 'One or more errors occurred.