starting problem

I've got a bit of a problem occasionally when starting but it's getting a bit more frequent, I'll go to start her up and the engine won't turn over properly at all, just very slowly as if there wasn't enough power from the battery, then i'll switch the ignition off turn it back on try again and it'll start straight up no issues.

Sometimes it'll keep doing it and I won't be able to start it up, other times it doesn't do it at all and is fine.

The battery was new this year and is fully charged, and I've cleaned the battery cables and connections up but still does it.

Could there be a spot in the starter motor that's damaged if that is possible? or could it just be on its way out?

I haven't had a proper look yet so was going to check the connections to the motor and everything are okay tomorrow but is there anything else that could be the problem before I come to the conclusion it's the starter motor?

Any help appreciated