Append data tool with excel (xlsx) CSV data on hosted feature layer created from .xlsx or .csv data leads to error "Error: There was an error."

Workaround

Through the following workflow, it is possible to use the append data tool with the same files:

1. Open ArcGIS Pro.
2. Use the Excel to Table tool on one of the excel files.
3. Right-click the created table in the content window and Display XY Data.
4. Export the created XY data to a feature dataset in a file geodatabase.
5. Share the feature dataset to ArcGIS Enterprise (as a hosted feature layer (copy all data: features)).
6. Go to the item page for the item created in step 5, go to update data>append data, and append the other .xlsx file which is not used during steps 1-5.

Steps to Reproduce