webpart app can not access data of sharepoint list

Hi 

I have developed app in spfx which access sharepoint list and shows data with documentcards in a grid layout on a page. 

When I deployed webpart on sharepoint side where this list is created app can not access this list

and console shows me 

 Failed to load resource: the server responded with a status of 403 ()

network tab of developer tools shows me 

1. code: "-2147024891, System.UnauthorizedAccessException"
2. message: "Access denied. You do not have permission to perform this action or access this resource."

however I have full access to the site and also to list. List had permission inheritance enabled, but I disabled that and added all groups manually, during investigation. 

What confuses me most is when I tried to deploy this app on other site, accessing still the same list app works and could retrieve data correctly. 

Any idea?