We have 3 node replica set(PSA) on Windows 2016 servers with MongoDB version 4.2.
Its featureCompatibilityVersion is 4.2 on all nodes before upgrade. Once it is upgraded to 4.4 all expect ARBITER remained at FCV 4.2 but on ARBITER it is automatically advanced to 4.4. Even if we set it back to 4.2 on primary using set command it is not replicating to ARBITER. is it default behavior or a known issue in version 4.4. This looks strange. Can we just disregard it.