Duplicate Custom Field Names in Team Managed Project is causing issues with JQL results

Issue Summary

If you create a custom field in a team-managed (formerly next-gen) Project and the name already exists in the company-managed (formerly classic) global custom fields, using the field in a JQL search is causing problems:

1. Relocating the field in the filter makes the custom field disappear.
2. CSV Export of the filter with the custom field added, shows duplicate fields.

Steps to Reproduce

1. Create a Custom Field in Team Managed Project, with the same name as a field in Global Settings -> Custom Fields.
2. Use JQL in Company Managed Project, add the Global Custom Field to the Columns of the JQL result.
3. Try to drag and drop the field to a different column in the JQL result.
4. Export the JQL results in to a CSV file.

Expected Results

1. While drag-dropping the Custom Field column - Jira should move the column in the UI.
2. While exporting the JQL results as .csv file - Custom Field should display properly, with all the field values filled in the column.

Actual Results

1. While drag-dropping the Custom Field column - the column disappears from the results.
2. While exporting the JQL results as .csv file - duplicate field with the same field name is displayed in the .csv sheet.

Workaround

• Use New Issue Navigator, which does not have this problem: https://community.atlassian.com/t5/Jira-Software-articles/Introducing-the-new-issue-search-to-Jira-Cloud-users/ba-p/2276375
• Delete the custom field that's created in the Team Managed Project Or,
• Simply rename one of the custom fields so there are no duplicates.