iTunes keeps adding songs to my iPhone that I do not want
Whenever I sync my iPhone to iTunes on my PC, in addition to the songs I want copied to my iPhone, iTunes also copies several dozen other songs that I don't want, needlessly taking up space on my iPhone. I delete those songs from my iPhone, but iTunes adds them back again on the next resync.
The annoying thing is that I don't have those songs on any albums or playlists designated for syncing, but iTunes syncs them anyway. How do I stop this from happening?
Thanks.
Windows 10 1809 running iTunes 12.10.4.2
iPhone 6 running iOS 12.4.5
Windows, Windows 6