The bug

Placing/removing a colored glass block above a beacon while beyond a certain distance from the beacon block in any direction, it takes the beam longer to update color than usual. When placing the block while within this distance, the color updates instantly as expected.

What I expected to happen

The beacon beam to update color instantly regardless of my distance to it.

What actually happens

It takes the beacon beam up to several seconds to update its color after the glass has been placed/removed.

How to reproduce

1. Place a beacon with a pyramid under it.
2. Go far away from the beacon block, horizontally or vertically, or both, but still have it in visible range. A distance of over 64 blocks was enough in my tests.
3. Place a colored glass block directly above the beacon. The height of the glass block doesn't seem to matter.
4. Observe the beam above the glass block.