Patrick,

I don't have a simple fix for this, but I have a few ideas for you to consider.

Maybe you don't play loud enough. In open jams, it often takes some volume to be heard, and until players earn the respect of having other people pay attention to their solos (and quiet down a little out of respect), sometimes volume helps get attention.

The usual strategy for "getting breaks" is to play some good stuff on backup (doing tasty fills, not too much, but just in the right places -- this sort of displays your musical competence), and when a solo opportunity is coming up -- that is, just as the chorus is ending -- look up at the lead singer as if to say "call on me".

If you've already been doing the above, there could be various other reasons for the snub. Anything from personality problems to "never liked mandolin" to ... you name it.

Another tack to take would be to talk with one or more of the people who usually lead songs, and in a private moment just mention you'd like to be called on more for solos. That takes a bit more social nerve to do, but it would probably work. Or if you let the discussion range to "I wonder why I'm not called on", you may be able to fish out whatever the reason(s) might be for your not getting asked. That kind of discussion can be ticklish, so try to keep your defenses down, and don't leave the person you talked to feel the conversation went poorly if they tried to give you some pointers. Mostly just say "thanks" and then chew on what you may have learned.

Best of luck. Let me know how it goes. I'm sure you can solve the problem somehow.

Pete