Sky/water flickering when connected to remote server

When Voxy rendering is enabled, I have constant, rapid flickering of dark colored patches in the sky and on the surface of water. I haven't been able to reproduce it yet in local games, only when connected to a remote server.

It's difficult to capture in a screen shot. This was the best I could manage:

You can see the sky issue clearly here. These dark patches randomly move around and flicker in and out at sub-second intervals. You can also see in the upper right quadrant that the surface of water sometimes does not render properly and shows the blocks underneath instead of the normal surface texture.

I am running MC java edition 26.2 with the latest Voxy as of today's update (0.2.17-alpha), on linux. though it has also affected previous versions of both minecraft and Voxy. My video card reports as Intel Corporation WhiskeyLake-U GT2 [UHD Graphics 620] (rev 02) using the i915 driver. I have no other mods installed.

Apologies if this is a known issue. I looked for similar issues that were already opened but did not see anything that seems to match precisely.

Start by reproducing the issue with Voxy 0.2.17-alpha on a remote server under Linux with Intel UHD 620 graphics and the i915 driver, then compare it with a local game. Investigate the sky and water rendering behavior; done means the dark patches and flickering stop and water surfaces render instead of exposing blocks.