This worked for me:
Select all the tracks from the album
Right click, select "Get info"
Click on the "Options" tab
Select "Compilation" and toggle to "Yes"
Click OK to exit
If that worked for you, great. Otherwise the tracks are all now randomly split up. If so, repeat the same as above, but this time change the compilation toggle to "No".
Voila. Your album should now be gapless.