vivoactive 4 clears screen before onUpdate

I've thought that only amoled watches clears screen  before onUpdate but from some time vivoactive 4 users have noticed about "flashing screen".

I have got mips watch (f6) and it still work the same way, simulator also not clear the screen.

So, is it a bug, normal thing on vivoactive 4 or soon all mips devices will run the same like vivoactive 4?