Hi Dominika,
Sorry for the inconvenience caused, we are able to reproduce the reported issues "iOS marker is moved after setting CustomView" & "MarkerSelected event is invoked twice" we have logged a defect report on this internally and the fix for these issues will be available in our Volume 2 SP1 release which is targeted to be rolled out at the last week of July 2018. We appreciate your patience until then.
Thanks,
Michael