Starter not engaging

Installed a starter a few months ago, many starts and worked great.

Now the starter will not engage and just spins.

Check to see if it.was secure to the engine and it was. Didn't come loose.

Pulled it out bench tested and seemed to work like it should. Gear moved out as to engage.

Included a pic to show it is gouged so not engaging.

Any suggestions would be appreciated.

Thank you