Welcome to TVPaint Community forums !

Hi, so I've seen a few differing topics about this issue and none of them seemingly have any solution that I've seen but I just wanted to know if anyone has found anything that works for them when it comes to fixing this issue. But whenever I try to draw lines every now and then a random straight line will appear for no real reason. I'm not using Windows Ink I'm using Wintab with Subpixel, but have tried with Windows Ink and the problem still exists and I'm using a Cintiq pro 16 dual screen setup.
This is a real frustrating bug and I really hope there is some sort of solution to this problem as it's making the program unusable, please help!

Do you have "Use Windows Ink" checked in Wacom's Mapping tab?

I am not sure if you are having the same problem as what I used to have, but my cirkels usually started with a linear line. Though, I don't see this issue when I keep my pen on the tablet.

TV-paint noted to me that they are currently working on this issue. They also noted a temporary solution and advised me to install the 32 bit version of TVPaint, which is apparently linked to the 64-bit build, usually fixes the issue. It definitely helped me and now I have smooth cirkels without any linear strokes at the beginning!