Data loaded by pbix

Hi,

We have a pbix file which is Published to PBI Service, so this pbix file have 10 Excel files refreshed everyday, some of them per hour.

I installed On-Premises Gateway, and created and added Data Sources, so just to check with you. Do I need to add pbix as a data source, or all 10 Excel files, or both? Because, when I loaded all 10 Excel files, it's giving me a message, for about 5-6 files, that I reached maximum of connections, and only some of them dont have this message.

Here is just pbix file loaded.

And this is a message that I have, if I try to load Excel files, used by pbix. Like I said, there is 10 files, and after 5 files added, it start to refuse the others, because the maximum conection is reached on this computer.