Changing OPACITY/FLOW to lower than 10% with SHIFT+0x gets stuck once in a while. If you try to set opacity or flow to below 10% with 0-x it will only register the x input.
For example:
I want to set my flow to 5%. I press SHIFT + 05, should go to 5%. Instead goes to 50.
If you select another layer, it gets fixed.
Happens randomly.