If iTunes works in it's current version, never upgrade it. Always is a problem for me as well with losing songs for years with every update.
I know this, be there, done that. My issue is with an ipad purchased in 2015. Till this moment I have not been able to upgrade the software on itunes. There is always an error. Now I can't get any new apps on my ipad. Maybe if I had been frequent with the updates I won't be stuck with 2015 iOS.