So since today photoshop has just not been working properly.
First I couldn't create images or open them, but I updated photoshop and it works now. However not properly, I can't do file > new I have to go to the start screen with open and new on it.
Now that I can create images (kind of) photoshop still isnt working. ALL OF THE TOOLS HAVE THIS PROBLEM.
The problem is that when I try to draw or make a shape or do anything, I cant do it properly. It either doesnt work at all, or it draws for a bit and then stops even though I am still holding down the left click. Then the part I have drawn disappears. Its annoying and not exclusive to the brush..
Sorry that Photoshop isn't working as expected.
Which version of Photoshop are you using?
I'd recommend restoring Photoshop preferences to default, refer this article Preferences in Photoshop
Let us know if that helps.