Remove a member from a share group affect roster group?

CC from “Openfire support”.

I don’t know anyone had seen the problem.

If I have a user ‘abb’ is located both in a shared group ‘GA’ and a roster group “RGB”. After I login using SPARK, the user ‘abb’ will display both under group ‘GA’ and ‘RGB’, which is right. But, if I remove the user ‘abb’ from shared group ‘GA’ in console admin page using ‘admin’. ‘abb’ will disappear both from ‘GA’ and 'RGB". It’s wired.

(Openfire 3.6.4, Spark 2.5.8)

After debug Openfire, I fount that the ‘removal’ IQ set command came from Spark client. Does anyone know the reasons?

Thanks.

update from “Openfire support”:

I tested the case several times in last days, and found it didn’t have something to do with shared group. It is removal member from shared group triggered the incident (if it’s not a case):

In Spark client, if user A and user B are both subscribed to each other with ‘both/to’ sub values and if user A remove user B throught 'remove it from my Roster", then user A cannot see User B any more in his roster.

Besides, User B cannot see User A in his roster too. It seems that User B received the ‘removal’ IQ and removed User A from his roster too. I don’t know if it is by designed.