The red props have some play movement ... is this a big issue  ?

Should I send my new Props back to DJI ?

Would you please take a short video to us? We will look into if it is normal, thank you.

I had  the same issue with my Inspire 1. So i moved to a different brand (Non DJI) and put carbon fiber props on.
I am flying with the new props for nearly 1 year and many hours of airtime and never had an issue.

Use the little Foam Pads that came with your 1345LS Prop Mount Upgrade, stick one inside the Prop where the Prop attaches to the mount. (I use about 1/2 of one of the little Pads) and your movement will disappear.