FPS degradation. I'm struggling to maintain 50fps on a high end device. (Galaxy Tab S7+)

This has so far affected every version since you moved to the renderdragon engine. Up until then it was buttery smooth even on my Samsung Galaxy Tab S4. I have just purchased a brand new Samsung Galaxy Tab S7+ and it starts in a new or established world (doesn't matter) at 80-100fps and within 5-10 minutes it is struggling to maintain 50fps which is unacceptable for a high end device. It has a Snapdragon 865 5G+. It should be like silk but it absolutely is not. The device I might add is running at default settings, optimised for FPS at 75% resolution in the Samsung game tuner. Screenshots are in the order of 'just started' to 'played for 5 minutes'. I moved about 500 blocks to load more chunks. Render distance is 16 and is default. I have tried 12 and it makes little if no difference. Performance is severely affected around villages as well for some reason.