Blades not cutting/jamming

Have you lubricated the blades?

Hedge trimmer blades require ongoing lubrication to keep the friction between the blades low to prevent excess heat. Ensure blades are lubricated before and after every use with a plant-friendly lubricant.

Unlike chainsaws, hedge trimmers don't have an oil reservoir, so the oil is applied directly to the trimmer blades.

Are the blades blunt?

If the blades are blunt, they need sharpening. To sharpen blades, take them to a sharpening expert. E.g. local mower servicing outlet or knife sharpening business.

How thick is the hedge you are trying to cut?

The hedge branches might be too thick for the hedge trimmer. Review the model and make sure it's suited to the material being cut.