For some delay algorithms, it might hard to tell but all delay algorithms are real stereo. It seems that your settings are alright. You may try some pitch algorithms. They are easier to tell the difference between two channels. H910, Quadrovox, Harmodulator, and Diatonic are good options. Set the MIX to 100 and pitch mix to A10+B10. Let me know if this works.
I realized what’s the problem in my setup – my outputs were set at center. I moved them to the left and right and immediately heard stereo. Thank you for quick help, that was totally my fault not the device!