Donating to a Cause vs. a Team
If a donor gives directly to a Cause you've created, that transaction will not be attributed to that Cause. In creating a Cause, you chose which Campaign you'd like that Cause to funnel into. A donation directly to a Cause will be attributed to the Campaign that Cause is funneling into.
To make that transaction go toward a Cause, it will need to be attributed to a specific Team. After someone has donated directly to a Cause, you can edit that transaction and change the attribution to go toward a specific Team within that Cause.
You can choose any team you'd like, or create your own team that you use to funnel some of these generic transactions into.