correct link without and Capitals?

Hi, I have a strange problem. On my live site a link like: https://s3-eu-west-1.amazonaws.com/something/Somethingelse+new.mp3 does not work but on my test side with a bit different plugin scenario it works. So I thought I have to go through the painfull work to check all my plugins for conflict.

But then I noticed that a link like: https://s3-eu-west-1.amazonaws.com/something/somethingelse-new.mp3 works on my live site. The difference is that it has no “+” sign in the url and no capital letters. Could that be the reason?

I need to know because then I could change my amazonS3 urls and actually use the plugin!

Thanks,
Demian

https://wordpress.org/plugins/wp-miniaudioplayer/