It will likely be fixed with the next release of iTunes. Or the one after that. You should use Feedback - iTunes - Apple so Apple can get an idea of how many users this issue is affecting. You might also want to go back to iTunes 12.7.3.
Step by step guide to rolling back to iTunes 12.7.3 on a Mac.
- Close iTunes
- Install iTunes 12.6.4, but don't run it
- Open Home > Music > iTunes > Previous iTunes Libraries in Finder, or the relevant folder if library is stored elsewhere.
- Locate the file with the date when you updated to iTunes 12.7.4, copy it
- Go up one level to the iTunes folder and paste
- Rename iTunes Library.itl as iTunes Library NEW.itl
- Rename the dated file as iTunes Library.itl
- Install iTunes 12.7.3
- Open iTunes
Your library should be restored to the exact state it was in when you closed it prior to installing iTunes 12.7.4. You can add the media folder to the library to import any additions since then.
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