You are losing weight very fast, 9 kg in 6 weeks averages at 1.5 kg or 3 - 4 lbs a week,
1-2 lbs a week is a good solid consistent loss. You should expect and mentally prepare for your loss to be a long journey not a short sprint. There will be some weeks you lose more, some you lose less, some you lose nothing or even gain.
Mounjaro helps to make that long journey more doable, it helps to reduce the hunger which makes a diet usually feel interminable, so that you are able to maintain long term consistency with a calorie deficit. But Mounjaro itself does not make you lose weight, it helps to improve some hormonal responses that prevent excess glucose being stored as fat, but doesn't actually burn or reduce the fat you have. That is all you controlling your calorie intake.
Water, water, water. It's boring, hard to remember for some reason and always the habit I seem to drop most easily, but you need to have lots of it. Your body uses it to break down fat (lipolysis), your muscles use it to heal the small tears caused by increased exercise, if you are dehydrated then your body will prioritise retaining it to ensure it has enough, so if you do not drink you'll gain weight on the scales. It won't actually be fat but it can be disheartening to see the numbers. So drink plenty.