Welcome bug when login in

I’ve tried to install Ubuntu mate 18.04 quite a few times and in different ways, but I always get the same problem.
When I boot up and log in everything works fine for a few seconds, until Welcome app shows up.
When it happens, the system goes back to the locked screen and I if I log in again the same thing happen over and over.
Is there a fix for it?
I tried download the iso again at least 2 times, tried UEFI and legacy mode, with or without dual boot and nothing happened, this bug continues.

Using the system through the USB works fine, it only happens when I install Ubuntu and boot up from the hd.

I don’t know if my explanation was clear, but if it is necessary I could send a video.

Hi Stup,
I don’t know if it can help you, but when I firstly installed Bionic I must change Marco to Compiz in Mate Tweak because the Welcome window was frozen. Maybe your compositor is not compatible with your GPU. Try to change it with different compositors. If you can, disable welcome in starting aplications.