ASIO-Guard peaking on Apple M1

I’m running Cubase 12 on an Apple M1 Studio in apple silicon mode (yes I’ve ticked and unticked it).

In the performance meter Real Time is hardly registering and Peak is only just registering. The ASIO-Guard reads about half way up the meter. While playing the ASIO-Guard spikes causing an audio drop out at random intervals. Even if the project is sitting idle the ASIO-Guard moves from half way to zero and occasionally spikes.

I don’t get this behaviour running cubase 12 on my intel i9 iMac (both have 64 gig ram).

I’ve tried setting the ASIO-Guard to High and it makes the problem a lot worse.
The buffer for my audio interface (RME) is a maximum.

Any ideas what could be causing this?