Hi Mariya,
Thanks for posting back with the requested information and confirmed the scenario with us. We also appreciate that you spent your precious time doing those tests.
As you mentioned that the internal ID will only appear with multi-Lookup fields. We are truly sorry about the inconvenience caused by this.
Based on my test, the exported multi-lookup field is displayed correctly if I choose to export to CSV as shown below:
If I choose to export to Excel, the internal ID will appear in the exported sheet:
In your case, may I confirm if you export the SharePoint list to .iqy file or the csv?
If you are exporting the SharePoint list as .iqy, please try export it to csv file and see how it works, vice versa.
You can try below workarounds for the issue:
- Export the list to CSV instead of Excel.
- Turn off the “Allow multiple values” for the lookup column.
- If you must turn on the “Allow multiple values”, you could use the Substitute formula to remove the "#;#;" in the excel after exporting to the excel.
- You could create workflow to copy value from the lookup column to single line of text.
For your reference: sharepoint export to excel shows internal id also for lookup field (microsoft.com)
Thank you for your patience so far.
Sincerely,
Rhoda | Microsoft Community Moderator