Unable to edit iTunes song info

Hello everyone, I hope this is the right place to ask.

I recently switched to a new computer and I am struggling to edit song info in iTunes. The songs are on my iPhone (running the latest iOS) and I have it plugged into my Windows computer (latest version).

I can't seem to edit any of my songs. I can't type in the boxes for "artist" or "song name" or anything. The cursor appears but I cannot edit anything.

I've checked my iTunes folder (the one under This PC > Music) and right clicked to Properties > Security. My username under advanced is set to "full control". On the main page, there is a black box in the "read-only" checkbox. Unchecking it does nothing; it returns if I exit. I've restarted multiple times, so it doesn't seem to be that.

Any help? I'm getting really annoyed!