Start with this.
1. Open Action Window > Tag
2. Select your tracks for one of the albums
3. In the Action Window > Tag, examine the Artist and Album Artist tags. Artist should be each track artist, Album Artist should be either blank, or the single value you want for the entire album. If the tag shows as [Varies], this means there are different values across the tag.
4. Examine the Album. It should contain the album name. Again, if it says [Varies], there are slight differences in the tag across the tracks. With the tracks selected, set the Album name directly in the Tag Action Window.
5. While you are there, you can also verify Date and Genre if you care to.
6. Finally, verify that the tracks for the album are in the same folder. You can examine the Filename (path) property to see this.