We are aware of this issue. We haven't figured out how to get rid of the location marker. The blue circle should get smaller as your devices finds its GPS fix. If you are on a device that doesn't have GPS you can turn the location service off since it doesn't do much.
You should still be able to drag into that area so just draw a marker somewhere else and drag it in.
Hopefully we will have a fix for this issue at some point as Apple fixes things.