Descriptive Problem Summary:
If an /atom/movable/O is using vis_contents on a /turf/B below (O is above B, and copying B) and O's removed and B is changed, B doesn't update on the client, resulting in an incorrect icon, name, etc and being unable to reference the turf through right click. This fixes can be updated through various ways, such as relogging, changing the z_flags of B, or sometimes moving Z levels.

Numbered Steps to Reproduce Problem:
1) Move player up Z level
2) Move elevator up Z level
3) Move player down Z level
4) Observe incorrect data and inability to reference the turfs in a right click verb

There is a DoTest() verb in the following:
https://cdn.discordapp.com/attachments/678826323728400394/ 783103080316796928/Vis_Issue.zip

Expected Results:
Client's turfs update correctly

Actual Results:
They don't

Does the problem occur:
Every time? Or how often? Yes
In other games? Yes, SS13 and test environment provided
In other user accounts? Idk
On other computers? Idk

When does the problem NOT occur?
If the turf below doesn't change.
Did the problem NOT occur in any earlier versions? If so, what was the last version that worked? (Visit http://www.byond.com/download/build to download old versions for testing.) Tried 513.1535 and 513.1520, didn't work

Workarounds:
You can fix it by updating the vis_flags of the turf to something else, reconnecting, or moving up 2? Z levels.