Firstly,
These machines do not have a dedicated GPU. They have an integrated GPU (iGPU) that is part of the processor.
Secondly,
I don’t think this is a driver issue. My guess is you are only running with one stick of memory which means the iGPU will be running in a degraded state and show “Intel(R) UHD Graphics”. To have it running at full performance which is when you would see “Iris Xe Graphics”, you need to have dual channel memory.
Here is the summary from the Intel site:
…in single-channel memory configurations will default to less than 80 EUs, in alignment with Intel® UHD Graphics branding.
Could that be it? Or are you in fact running in dual channel mode?