Error when clicking the Lines tab in Invoice Enquiry menu. "This is a read only flexfield. You canno

There is a custom trigger to insert value into the Business category Valueset in the Invoice_Lines, When querying the created invoice through Invoice Entry - Batches, we could see the business category value getting populated in the Lines tab.

When querying the same in Invoice Enquiry screen, and clicking on the lines tab, we get the error as "This is a read only flexfield. You cannot change any values in the flexfield"