Weird Solo behavior

[Billy86]

Why would a track, when soloed, prevent every other track from soling along with it, AND mute itself when you try to solo anything else with it? It only happens with one track: EZ Bass, inserted as a simple instrument. 

1. Dim solo off
2. Exclusive solo off
3. Solo EZ Bass track... result: as expected, plays in solo
4. Solo ANY other track OR buss... result: nothing will solo with with EZ Bass, AND EZ Bass goes silent, even though EZ Bass is still soloed, and the console view indicates the presence of audio in the track.
5. Un-solo whatever track or buss I soloed to try to get to sound with EZ Bass soloed, and EZ Bass is audible again.
6. Un-solo EZ Bass (so, now nothing is soloed) and everything plays fine.

7. Turn on DIM Solo... none of the above happens. If EZ Bass is soloed with Dim Solo engaged, I can solo other tracks to play along with the EZ Bass track, and non-soloed tracks drop in volume according to my setting for that function. 

There's so sidechain anything coming out of EZ Bass to impact anything else. It's a standard set up group tracks (drum multi's, guitars, keys, etc.) going into group busses, those busses going into master buss. Putting EZ Bass in solo  has the same effect as above  on the busses.

I don't get it. Help please?