I built something similar (Chua's circuit) for an electronics course in college[1]. It was a lot of fun. While testing it, we couldn't get it to display the phase portraits on an oscilloscope for a long time, and then we realised we were using a modern "digital" oscilloscope. I think the (high but finite) sampling rate was not enough. The professor found an old analog one from the 80s in his lab and then we got the pretty phase portraits. This site was super helpful at that time (2016)[2]

[1] https://karan.sh/res/Chua_Circuit_report.pdf [2] http://www.chuacircuits.com