I am sorry, but the fact that brand Cowboy 4ST brand and model was kept out of the headline--seems entirely deliberate.

That stated, it looks like a bike that was over designed and under engineered. The motor and batteries have additional weight that places additional stress on many of the components.

Noting that when using aluminum, if it is indeed the chosen frame material, steps must be taken prevent cracks not only because of fatigue life, but frames should also be heat treated after welding to relieve internal stress.

A great many single downtube ebike frames have marked guesseting, as well as a thicker vertical cross section...to prevent such things from happening.