The problem was found in garbage collection. The time between purging pending kill objects was set to 1 second for testing purposes and left out. For anyone else experiencing similar ‘hitches’ every few seconds, make sure that ‘Time Between Purging Pending Kill Objects’ is set to its default of 60 seconds in Project Settings → Engine → Garbage Collection.
Or better yet, disable GC if not needed to eliminate these hitches all together as specified in the following document: