I decided to install elementary OS 5.1 Hera on the new HDD I just found laying around (so, I will keep Windows 10 on my SSD). I have downloaded the .iso-file from the official elementary.io website and used Rufus to get it on my 32GB USB stick. Everything in the installer went fluently until I got to the part where you choose between the four location-options (overwrite Windows, use LVM, something custom, etc.). When I move my mouse, my cursor also moves. But, when I click it doesn't register that. I have selected both 'Download updates while installing Elementary' and 'Install third-party software for graphics and Wi-Fi hardware and additional media formats', so I don't think this has to do with any drivers.
Intel Core i5 8400 (2.8GHz)
NVIDIA GeForce GTX 1060 3GB
Windows SSD: 500GB Samsung 860 EVO
Windows HDD: 1TB Seagate Barracuda
'Elementary' HDD: 360GB Seagate