Clunk when going into reverse - please help!!

[matt643]

Hi

I've got an automatic 2019 R Line Edition estate - absolutely love it!

When I switch into reverse and then start moving there is a big clunk that sounds as though it's coming from somewhere beneath the gearstick area.
When I move back into drive it sometimes does the same but to a much lesser extent. It only happens when moving from D to R or R to D - not being in reverse then stopping and moving in reverse again.

I drove it over a pit for my mechanic and he couldn't see anything. Has anyone had similar or got any advice please?

I don't know how to get it diagnosed and don't want it to be doing damage the that will cause me to break down, or be braking something that's going to cost £millions to fix!

Help much appreciated thanks!