RQMv4.0.2 Freeze TCERs or Freeze Test Plan

After all test cases in a test plan are tested, we then retire the test plan, so we do not expect the plan be changed in any way.
That however does not stop TCERs from being run. As a result, the test plan was changed because of the test result produced by the execution of the TCER. If we generate a report for the test plan, the number of passed/failed are different.
This is kind of 'freeze the TCERs or the test plan'. I can open an RFE if I do not get positive answer in this forum.
Thanks.