Map Waypoint don't work when you make the maps bigger

map waypoint won't work when you make the map bigger

What I expected to happen was...:
Waypoint should stay no matter how big the map is

What actually happened was...:
When i made my map bigger all the waypoints vanished 

Steps to Reproduce:
1. Make a Map
2. Make a waypoint using a banner
3. Make the map bigger using the new cartography table