Bug with PUT requests on grp

[iwakura1ain]

There seems to be a bug with PUT requests on groups. Whenever I send PUT requests to modify grps on the server, the proper values aren't saved and instead it shows me wrong values.

Attached below are screenshots of the process.

- First, I created a group with members [a, b, c, d, e].

- Then PUT requests are called to modify members. After modifying, I get the correct response back with properly updated members.

- Next I send a GET request to the same group without modifying anything, but the members aren't updated. Instead, it's showing the old members of group bug [a, b, c, d, e].

- Again I send the same GET request, but this time the members are [a, b, c, d, e, f], which were members of a previously deleted group that should not exist on the server.

[iwakura1ain]

I had to resort to using a workaround where instead of modifying existing groups, I deleted and created the same group again with modified members.