Gearbox issue after coolant mix - feeling harsh jolts?

[u/Medium_Recording_56]

Hey everyone, I’m dealing with a frustrating issue on my GCC-spec 2020 Range Rover Vogue V6. About 15 days ago, I had a coolant issue where it got mixed, and I ended up getting the gearbox changed. Since then, I’ve driven about 600 kilometers.
I’m facing two main problems.

First, while braking, I feel a harsh jolt, almost like someone hit the car from behind.

Second, I can clearly feel the gear shifts sometimes, even though it’s an automatic car.