Psychopy - why doesn´t my timer reset during pvt?

Hi!
I´m just a begginer and i need to make a PVT for my project. I downloaded finnished pvt from this page to make things easier:

I didn´t change anything, but it doesn´t work as it should. The timer that should be showing reaction times in miliseconds shows some crazy numbers. And it seems to me like the timer doesn´t even reset, because the values of reaction times are getting higher after each stimulus.

I´m sorry if it´s a stupid question, but i don´t know how to continue.
And it seems like it works for the author and also someone on youtube, who used the same link as me.
It sounds like it might be a problem with my program or computer.

Thank you for any advice!