Freelander starting problem

hi guys I’m new here and looking for some of your experienced help.
I have a 2001 1.8 freelander ES. I
I have replaced the starter but still getting the same problem.
It starts sometimes but most times the starter kicks out and jams them nothing. It won’t click or crank.
If I hit the starter it will start.
Any help would be appreciated.
Thanks in advance
Andy

Just a quick test put earth using jump lead from earth on battery directly to engine or gearbox to see if earth is poor after that maybe try with jump leads to see if battery is low

Thanks Yoda. I’ll try that