Hi,
I have found what I believe to be a bug in the way that Alteryx recognizes field names from an Excel binary file. In the attached file I have added 2 data sources. As you can see they are identical, with the only exception that one Excel file is saved as .xlsx and the other as .xlsb.
For some reason Alteryx renames the field header coming from the .xlsb file, converting the period (.) to a hash (#), so that instead of "Acct. Manager" the field name becomes "Acct# Manager"...
To be fixed in the next release?