How to Retrieve a group name by UUID?

Yes the function do not work here but here is one way you can do that .

a!localVariables(
  local!allGroups:a!forEach(
    items: getallgroups(-1,1),
    expression: {
      id:fv!item,
      UUID:getgroupuuid(
        fv!item
      )
    }
  ),
  index(
    local!allGroups,
    wherecontains(
      "9018b532-810c-4f06-becb-948a954b8eb2",/*uuid for the group*/
      touniformstring(local!allGroups.UUID)
    ),
    {}
  )
)