Why cant I join when both of my teams compete

I am member of 2 groups.

Once a message came saying that there is a match between the two groups (New team match - Registration Open!!!)

But I could not join both the groups. (The registration did not close).

Could anyone find me a solution on why I cannot join atleast any one Team match group?

Conflict of interest?

I understand

Thank you very much

So, it means that if I withdraw from any one group, I could play for the other.

Actually it is a long waiting problem that chess.com is still trying to fix.  When a team match starts and a player is member of both teams he (or she) should have option to choose (as available in case of vote chess in similar situation.)  I started a similar thread some 4 or 5 years back, but still Chess.com is 'working' on it, seems. :)

http://www.chess.com/forum/view/suggestions/team-matches-for-someone-who-is-member-of-both-teams