When I engage the blades on my ez4824 the blades intermittently stop cutting particularly in higher grass. Do you think this is a loose belt problem? Thanks.

Remove belt tension and test the tension pulley arm (55) rotates freely and spring (148) is in place. See attachment.

Husqvarna (USA) lists the belt as discontinued and no substitute. I find the belt should be 92.5" in. If measurement is questionable then take the belt with you to a local supplier and compare lenth of old belt to a new belt of known length 92.5".

It sounds like you got into a job that was too big for the machine, and you may have either burned up the drive belt, or toasted the transmission or clutch.
Someone knowledgeable about such things should be able to raise it up in the air and look underneath and discover which problem you have.
God bless your efforts.

or you sure blades on right sometimes hard to tell if yes you have bad bearings

Your deck belt needs adjusted.

Sounds like a broken shear pin in the drive pulley. Check the belts and see if they are slipping. Broken shear pin will not let the blades spin under pressure. .

Is this the first time cutting grass with a lawn tractor?
How tall of grass?
Use the grass cutting heigth adjustments on the tractor to a higher setting when cutting tall grass. Cut again to a lower height setting on the second pass. Grass higher than your tractor is not good for your tractor. Follow the manual instructions for best results.

Most likely what you did was burn one or more spots on the belt. When the blades and belt stop turning, like in tall grass, the engine doesn't stop and will burn flat spots on the belt at the engine pulley. Every time the flat spot hits a pulley, it will jump and can set up a bad vibration. Run your hand around the sides of the belt or take it off and you will feel or see the thin spot(s) on it. Replace belt.

Is the belt on the pulleys ? If so your cable is broke its what engages deck belt

It sounds to me like a very loose belt or very worn out belt and also an adjustment problem.

the electric clutch that operates the blades needs replaced