iTunes not uploading M4A files

This has been an ongoing battle for around a year, and is extremely inconsistent so I can’t quite pinpoint the source of the problem.

Basically, when trying to upload files with M4A formats (that obviously aren’t on the iTunes database/match) it provides an “error” when attempting to upload. There is an icon of a cloud with an exclamation point inside it and the “upload status” of the File Info section also says “error”.

No matter how many times I delete and re-import, and try numerous troubleshooting methods, nothing works! However, every single MP3 format file imports correctly without fail—even when an MP3 and M4A on the same album are imported, it successfully uploads the MP3 but errors the M4A… Thus it shouldn’t a problem on my end. Again, this has happened many times in the past and I have found no solution, so if anyone else has had this issue or knows how to solve it please help me! ❤️

(And no I will not convert the m4a to mp3, I require to maintain its original format)