I have assembled a Bafang BBS02B (750W) on a Bacchetta Corsa recumbent bicycle (see photos). The drive is less than a year and a half old and until 09/16/2019, it has been operating flawlessly. My Bafang edrive is now starting to buck, surge, and hesitate under power assist pedaling (and the throttle button/lever). The power output at the different power settings no longer match. A setting at 2, for example, provides the same wattage as a setting at 6. CRAZY! At one point, the system flat shut down on me. A couple days later, I got it back on again, but the surging, hesitation, etc., is still there. The Bafang let me down on a long bike ride causing me to push it up a couple hills. I cannot have this happening and I must correct the problem. Has anyone out there ever experienced this condition; and if you can give me any advice, I would certainly appreciate it. At the moment, I am suspecting the controller.