Microsoft To Do Lists problem. They shuffle themselves and confuse all tasks with no apparent logic

For quite some time now the "My day" list (with almost 300 items) has been messing up the order of the tasks by shuffling them without any logic (for me of course).
When the next day (after I reset the order of the List) the "My List" appears, the same event happens.

Also, some tasks disappear from the List "My Day" without permission.
Please, note that there is no sorting rule in the list.