Problem with brush or with unity

Hello i have a problem. Nothing with scripts or textures or with nothing. Just somethimes when start unity my paint with looks like on picture one and sometimes when start unity it looks like on picture two , blue and brush have squares on end of circle. What can be bad ? i have no idea

40262-totojedobre.png

40263-totojezle.png

Ok, i found mistake. I used script which maybe changed some options in unity. Then it works good , but when i closed unity and reopen script doesnt change this things and it didnt work.
So its ok now. Thanks