Connecting to on-prem SharePoint 2013 doesn't work and says 401 Unauthorized.
SharePoint site is using SSL and is path based. Login I'm using is correct and able to visit SharePoint site that returns 401 error
Error message is just "401 UNAUTHORIZED" with correlation id. It pops out when I try to "Connect to a SharePoint site" (creating new App). Creating connection (where I can select proper gateway) is working but connecting to https://portal.domain.com/ ends with error. The account I'm using has access to site and is also able to visit the site in browser. The account is farm admin and has Full control through User policy on web application.
I tried with 3 colleagues accounts and it didn't work, I always get the same error message.
The gateways was installed and works perfectly (I also use it for Power BI)