Sun position related shadows update at a very low rate

Date & Time: 08 October 2020
Frequency: Always during daytime
World name: n/a
Character name: n/a
Retainer name: n/a
NPC name: n/a
Monster name: n/a
Class/Level: n/a
Party or solo: n/a
In-game time: n/a
Area and coordinates: Anywhere
Housing: n/a
Steps:
1. Wait for the ingame sun to be up
2. Locate a shadow being cast by the sun and zoom in on it
3. Observe that the shadow only updates roughly 10 times per second

If you are having trouble seeing this, record the game using something like OBS and step through the recording frame by frame.
You should be able to see the shadow stay in the same position for multiple frames.
For comparison, have some animation that runs at the game's framerate (like the gatherer buff that prevents hostile mobs up to 4 levels above your own level from attacking)

Shadows cast by moving objects, such as a player dancing, do update at the framerate.
This leads me to believe that the shadows actually do update every frame, it's just the sun's position that isn't getting updated every frame.
I have also observed the stars during a clear night not updating their position smoothly, but that effect is extremely subtle. I suspect this has the same cause as the shadows cast by the sun not updating every frame.


Connection Specs
- Type of internet connection/provider: n/a
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Browser Information
- Name and version of the browser currently in-use: Google Chrome
- Internet Explorer Version: n/a