Periodic rubber-banding / position rewind on macOS 26.5 (Tahoe), caves worlds only

Platform: macOS 26.5 (Tahoe), Apple Silicon (MacBook Air, M4, 24 GB RAM)
Game Version: v728321 (64 bit)
Mods: tested with all mods disabled, issue persists

Issue:
When hosting locally with caves enabled, my character periodically "rewinds" — I move normally for a few steps, then am suddenly snapped back roughly 3–4 seconds to a previous position. This repeats continuously and makes the game difficult to play. The surface shard appears fine on its own; the problem only appears when caves (the second shard) are present.

Setting Lag Compensation to "None" stops the rubber-banding, but replaces it with heavy input lag (every action waits on the shard), which is not playable. 
Hardware is not the bottleneck — this is an M4 MacBook with 24 GB RAM

This looks related to the previously reported (and marked "Fixed") macOS Sequoia 15.4 synchronization/rubber-banding bug, which was also caves-specific. It appears to be present again, or never fully resolved, on macOS 26.x (Tahoe).

Hosting the same world on a remote dedicated server (Nodecraft) with the MacBook as client only — works perfectly, no rubber-banding.