Rekordbox Missing File Manager Not Picking up missing Tracks in the same folder

Rekordbox 5.5.0 64bit

After moving my music library location of about 3000 tracks I used the Rekordbox Missing File Manager to relocate the tracks (File>Display All Missing Files>Select All > Relocate.) Found the file, pressed okay and yes to 'find other missing files using the location of this track'. 

RB matched approx 1450/3000 Tracks and failed to find the other 1550 songs even though they're in the same folder. I can relocate each track manually but that's not something I want to do. 

It would be greatly appreciated if anyone could help me out. Please & thankyou!