as an s18 rider I'm grateful that you posted about this.
I've gone about 300 miles now without cut outs but that's certainly a larger risk with a powerful motor and battery with 40% less power in the batteries than the original 18xl this board was designed with...
Would you give more details about the original cutout? Speed? Incline? Riding weight? Were you passing someone?
More information will help people like me not to crash.
For getting over the initial fear of getting back on, maybe try full gear in an open grassy area? Falls on the grass are not as bad. That's where I try new stuff with my s18.