Many users have been complaining they can not upload their large music songs to iCloud Music Library. I had faced the same problem and finally found out the solution after hours chatting with Apple supporter.
I got failed to upload the a whole album including 10 tracks to my iCloud Music Library. Each song lasts about 25 minutes and is 70-90 Mb in size.
Whenever I attempt to upload the songs, an icon (“!”) appears next to the song. In your case, if you click on “!”, you are noticed that it could not upload because of an error.
What is the error and how to fix?
You can not upload large tracks to your iCloud Music Library because you do not have an ADSL ISP which is fast enough for sufficient uploading speed. The best way to solve the problem is switching to another ADSL ISP (using another WiFi network is an example).
However, you can use Google DNS to improve your current uploading speed.