Yes, I noticed that. But the question is if you are able to correctly access the sheets. Maybe give this a try below.
Here’s an example with an app I copied to help with.
Source dropdown and choose “browse for more data”:
The “GET DATA FROM” screen appears so I can select location I used in past:
Choosing Google, I get the following screen. Note that I cannot navigate anywhere else on My Drive.
If I back up to the “GET DATA FROM” screen and choose “New Data Source”. I am presented with a list of sources to choose from. Choosing Google and then re-authenticating, (NOTE I needed to do this twice) I can now navigate within the Google drive to choose additional workbooks to add to the app as Source Paths or re-select the original source.