EPM Application Roles assigned to IDCS Groups disappear overnight?

Summary:

EPM Application Roles assigned to IDCS Groups disappear overnight

Content (pleaseensure you mask any confidential information):

We assumed that we could assign EPM Application roles (e.g. Ad Hoc - Read Only User) to IDCS groups now that they are visible in Access Control. However, although the assignments appear to work, by the next day, the assignment has just disappeared. Task List Security, Business Rules, Forms and Dimension security all maintain the IDCS group assignment, just not the application roles. Have only tried with FreeForm services so far (with both JIT and non-JIT enabled groups) but were intending to use with Planning, EPCMCS etc if it works. It feels like a bug and I wil raise and