I think that you mean that it does not open the fron panel of the subVI and when it is opened by you, it does not update the data on its front panel they way you would expect.
Reentrant VIs are like regular VIs in that they have a front panel and a block diagram. The are different from non-reentrant VIs in that they have multiple data spaces. Each "instance" of the reentrant VI has its own data that it keep track of. Since one VI can have several sets of data, it does not know which one to show on the front panel. So, it doesn't even try.
Something you could do to work around this would be to create a VI that you can use just to display data. Feed it the proper data and let it be the UI. This VI would not be reentrant.
I hope that th
is helps,
Bob Young