I found the bug. Initial value was in integer numbers, but when I cast it boolean, everything works perfectly. Something new every day :)

No worries j I will find the solution somehow, thnx for help anyway.

j Once, but how does this works correctly locally? Values are ok, but checkbox is what confuses me.

That's weird thing here j Screenshot

I will try that tomorrow, and let you know if it works.

j what's yours solution?

In my case, no. I went to collage for 4 years, didn't show ambition so I decided to start on my own. I had been on many job interviews and neither one asked me about CS Degree.

Just use React!

Thnx Cho, I agree, it's totally strange behaviour, especially because it works fine on local machine. Here is my screenshot with value 0 but checkbox is checked Here is my screenshot with value 1 and checkbox is checked, that's fine I will consider your suggestions.