I bought a raid controller. It is “StarTech 2 Port PCIe Controller RAID controller”. It is a Marvell based RAID controller. It does not function well. I could not configure it. I cannot enter the configuration by pressing ctrl + m after BIOS enumeration. I researched it a lot. Many people complained about similar problems. They also say it is a low profile RAID controller. Therefore I want a proper and fully functional RAID controller.
There are very specific reasons for why I need a PCIe based RAID controller. Mostly for research. So, please let us not discuss why I should NOT get one 
I also do not want to use motherboard’s RAID controller.
My motherboard is Gigabyte Z390 Aorus Master. Would you please recommend me a proper RAID controller? The budget isn’t important. What is of paramount importance is that it is fully compatible with modern motherboards and functions well.