The engine periodically puts itself into Reduced Power Mode.
The reduced power mode is usually related to a Check Engine or ABS light coming on. When a problem is detected, the engine goes into reduced power mode to try and allow you to get to a safe stopping point. I recommend having a certified mechanic, like one from YourMechanic, test your vehicle and scan the computer system to see what codes are received. From there, they will be able to officially diagnose your vehicle’s reduction of power and let you know what repairs will be needed.