10 fps is in Hi+ not Hi
But not with electronic shutter
I also read that this is only with compressed lossless raw and jpg, if you are using uncompressed raw it's 8fps.
Could not find the Sony doc and I've not tested mine but try a few more options (Mech shutter and different Raw types and Hi+)
AI Overview
Sony A7R V - Max FPS by File Type & Shutter Type - Alpha Shooters
The Sony a7R V can capture still images at up to 10 frames per second (fps) using the mechanical shutter and 7 fps with the electronic shutter, according to DPReview and Imaging Resource.
