Cypress-Cant execute calculation.

[stick710]

I have problem testing some WebApp with cypress. App has button "RUN", and when it is clicked it pops out alert "put some variables in rows and columns". When I put some variables into fields and then again click "RUN" it should execute calculations and put result in "grid". But in tests when I click on "RUN" button it starts the calculations, and shows -(xhr) POST 500 /crosstab/execute- and he never finishes calculations and put it in grid view.

I dont have source code for app, im using inspect to finds selectors. Button works and shows alert when fields for row and column are empty, but when it needs to start calculating something in going wrong. And that problem show only when Cypress is doing that, on the actual WebApp all functions are working fine.