Almost half of my To-Do tasks have disappeared ?!?

[RipPipPip]

I use To-Do on 2 PCs (Windows and Linux) plus on Android device...

it was many months from now that on any of them I had DIFFERENT count of tasks....but today happened a disaster - I see that almost half of my tasks disappeared (and some of them I had many years from wonderful Wunderlist times) - logging out and in caused that I just have same count everywhere but...50% of my previous I do not have (anymore???) now!

And it looks like that these were "chosen" in a random way???

WHAT IS GOING ON, pals?

[#2]

PS01: Hahahaha: The situation seems to be developing: I have just "shown" 30 tasks that had previously "disappeared". There are still about 150 tasks missing, but I'm beginning to have some hope ...