Hello @fayeakuzzaman,
thanks for the feedback. Unfortunately I was already using the storefront theme and deactivating the plugins and clearing cache and cookies didnt resolve the issue for me.
If I try to login as a customer it reloads and I land on the same page still not logged in. If I try to login as a vendor or admin I land on the vendor dashboard page. Maybe the issue is here? Am I supposed to land there? And is the user not landing there because he has no permission or simply has no dashboard?
Login through any other way than on the account page seems to work fine though.
Thanks for your input. I found a plugin that supports Role based pricing