Sync music on my phone

[styleruk]

Hi, wondered if anyone can help here. I have a folder on my pc with ~40Gb of music that I have on my phone too. So I was fed up with using isync to sync my android phone to itunes and mess everything up.
Thought I'd use freefilesync to do the same task. But what I need is when I add a song, it needs to go over to the phone on next sync, then if I delete an album, I want that to go too.
If I use 2way sync, it want's to put the album back on my pc from my phone that I deleted from the pc. So that's no good. I thought it would look at the date it was deleted and remember that so it knows not to put it back again.
So I had to do a mirror sync to update and that would then remove the folder from my phone, however, It seems to be spending hours putting everything back on! If that's the case then it means my phones music app will think it's all new and will have to scan it all again.

Guess my issue is, how to get it to actually sync? By sync, I mean if I delete a folder or file from one or the other, it remembers that across both devices.

Currently what FreeFileSync is doing, I could do manually by just copying the entire library each time to my phone!

PC windows 10
Phone, Samsung Z flip. Connected via USB-C port.
Music player on phone; Rocket player.

[xCSxXenon]

Try comparing by file size. Sometimes dates get weird on mtp devices. Or, you could leave it as it is, let it run the mirror, even if it does end up overwriting some data with the exact same data, as it should only do that the first time

[styleruk]

Sometimes I will delete files in the device, so sync is what I need. I'll try by file size.