When the game autosaves, all chunks load considerably slower than before, no matter if they are explored or not, in testing. Block lag also is a common occurrence as block placing and breaking is often much slower or doesn’t happen at all during autosaving. As well as this, sound delays and temporary game-freezes are common, with frame-rate drops occurring. I believe this may have something to do with the game purposefully slowing down to help speed up the process of saving, but when autosaving on the switch occurs every 10 or so minutes, it can be really annoying. I often find the game taking around 5 minutes to save, with only 5 more minutes of downtime before the next autosave leaves the game unplayable. Either fix the performance issues, or increase the time between autosaves.
Note this bug is at its worst when chunks are being loaded and updated quickly, such as using an elytra, or breaking and placing any amount of blocks