Yeah it's really strange.
Like I say, loads of songs have Parenthesis in the title no problem. And I've not had this issue until maybe two weeks ago. I'm not sure what's changed. I've been trying to update a song title (either in the main Music tab by clicking on it twice or by right-click > Edit and changing the track title tag and hitting Ok) but nothing seems to work. The filename still remains with the parenthesis but it doesn't seem to want to display it in MusicBee.
See below RR7387 - I'm unable to change the songs to have (Remix) after them.
On RR7400_LA041717 the tracks have parenthesis no problem except for the last track Copter.
Really strange and really frustrating.