Same issue, everything was fine in my nintendo switch until yesterday, when the update for 1.19.60 was downloaded and applied. From that point most of my saves are unplayable; saves weighting more than 15MB lag every few seconds; small saves (3-5MB) do not lag that much, but still lag
I have the game in SD card. I tried to remove the SD card, totally uninstall and then reinsert the card, but I keep having the same issue
BR
/// RFGF
Some additional info on top of my previous comment: As game was unplayable, I deleted ALL my worlds (around 10). Then I created new worlds, I have been playing in 3 of them and so far there is no lag... but I have not built much stuff on them anyway. May the issue appear mainly if we have worlds created from previous versions?