When travelling throughout the world, chunks often take ages to load, will load entities long before actual blocks and will often fail to load entirely for several seconds, as seen in this video- https://www.youtube.com/watch?v=IB3yXtrXd9s&ab_channel=Nebagram

Also, the game can often take several minutes to save upon quitting. I've updated Java to the latest version, restarted my computer and even tried it in Optifine, but there is no improvement.