Why iss the telephoto lense sticking. It works well on occasions.

If it’s been dropped then the barrel could be distorted, giving the problem. Otherwise, your best hope is that it’s dirt, sand or some other contamination between the barrel sections. Rather than repeating them, see the hints we have at https://wiki.restarters.net/Compact_came...

Otherwise it could be a problem with the zoom motor or gears, which is going to be more challenging. Follow this guide Remplacement de l'objectif du Panasonic Lumix DMC-ZS25

to remove the lens. Test the zoom function with a 3V battery as described in the finasl step of Disassembling Canon PowerShot SX200 IS

On the back of the lens you’ll find 4 or 5 black screws around the periphery which you can remove to take the back off and examine the gears, should this be necessary, but refitting may take a little patience.