Issue with a!pickerFieldUsersAndGroups while selecting users.

My use case is to pickup users from only particular group using a!pickerFieldUsersAndGroups, i have encountered some weir ed issue. Below is the use case.

I have four users in a group.Lets say User A, User B, User C, User D who are part of group XYZ.

When i try to search i have problem with only two users lets say User A and User B, they can be searchable by admin users and them selves but not by other users.I tried all the possible ways in debugging by creating new group etc . Added the same user to other group and configured that group still the user is not visible in search. Its the issue with only those two users in the group.

please let me know if any one has encountered this issue or any suggestions?

i have configured  a!pickerFieldUsersAndGroups as below.

load(
local!assignedTo,
{a!pickerFieldUsersAndGroups(
label: "Test Groups and user selection",
maxSelections: 1,
groupFilter:togroup(XYZ),
value: local!assignedTo,
saveInto: local!assignedTo
),
a!buttonLayout(
primaryButtons:{
a!buttonWidgetSubmit(
label:"submit"
)
}
)})