This is not a bug, it's a missing functionality. SimpleMoveTo has absolutely no networking support
SimpleMoveTo does not work on Clients.
1. Create a new Top Down Blueprint template project
2. Set the number of Clients to 2
4. Click to move on the Server
5. Click to move on the Client
The character on the Server moves to the click location, but the Client character does not move.
Head over to the existing Questions & Answers thread and let us know what's up.