Ubuntu 16.04 hides cursor when using graphics tablet
I've finally figured it out. The problem was that my mouse was connected via PS/2 port and my tablet was connected via USB. I've connected my mouse via USB and cursor disappeared permanently. But after system restart everything works perfectly fine. I can control my pointer using both mouse and tablet and nothing disappears anymore. Looks like Xorg can't handle input from PS/2 and USB at the same time.
But Ubuntu 15.10 had no problem with it. Machine with 15.10 on which I've done testing before is a laptop with touchpad connected internally via PS/2 and I was using exactly the same USB tablet. There were no problems on that machine.