Issue with CSS loading

I'm working on a Gatsby app in .tsx format and I have set up an authentication like this one [here](https://github.com/marcomelilli/gatsby-firebase-simple-auth). For some reason when I click on login button (especially in Brave browser) my cursor goes kinda crazy im not sure it's any z-index related because the cursor goes from normal to pointer to like when you are writing for a while and then it stops. Has anyone had this issue before? Thanks there