ManmadePlatypus

Looks like a "works as intended" situation due to misaligned portal coordinates between overworld and nether. Nether portal should be rebuilt at exactly 1:8 coordinate translation, compared to overworld coordinates, to prevent this from happening.

I also have the mining lag along with rubberbanding (blocks reappearing). Previous to this update, this lag would usually only occur with 2-3+ players online, and only in certain areas (usually near high-entity zones). Now the lag and rubberbanding is global, and happens with only 1 player online. Netherite pickaxe now feels like an iron pickaxe due to the reduced mining speed. Everything is sluggish though, not just mining blocks.