Devourer such a large machine will cause the light calculation is very large so will be stuck in the save for half an hour, save in the inside of things will remain operational, thus leading to save while calculating and operating, and in 1.16 can be saved normally will not reach more than half an hour, in 1.17 on the save need to "Carpet" and " Carpet TIS Addon" mod, a command /carpet lightUpdates suppressed to reproduce it, and the use of a large number of machines to card the light calculation, because the light calculation is not calculated in the main thread will lead to save while calculating and operating and thus stuck program, if merged in the main thread, so that the calculation is smooth and Save, there is a video on bilibili is also a light calculation problem from: https://www.bilibili.com/video/BV1bY41187X9(50x50 big devouring)
CPU running calculation efficiency is not very high or stuck thus recurring out