Your information is too brief, you better post sufficient information so other users can test, including:
- Table schema of the main table and the lookup table
- Edit Tag and lookup table settings of the lookup field
- Error log (make sure you have enabled Debug and check HTTP response in your browser as suggested above)
Note: Make sure you use the latest version (v2022.2 as of today).If you are a registered user, you may also send your project file and other required information to support directly.