No match with content ID, music video question

I have created a lot of music videos from remixes of older songs from the 1990s. I have uploaded them all to my test YT account as private videos with random titles/description and a lot were detected by YT content ID for the song but about 100 of them it hasn't detected and they have been up for a few days now.

I want to upload and publish these music videos which didn't get a copyright flag to my other channel but obviously if I do this I will need to put the artist and song names in the…

No match with content ID, music video question