Reflection probes become almost irresponsive or extremely slow to update while editing EEP. ( Haze setting simply slows down probes).

Instant repro:

Same or similar happens after long sessions, default region probes just become somewhat irresponsive.

The only fix is to log out and back in... or go make a coffee and wait for the viewer to decide to update all of them.

Edit:

This is another landmark from a buddy @ Venus Tattoos (angelo.venus)... there it is really easy to notice default reflection probes fighting each other. (Place the camera inside the building around the center area, and rotate around, will also notice some sort of flickering... similar to another ticket with a large mesh building.)