Apple released a new processor architecture, called the M1. The WhatPulse client works on the M1 but can display unexpected behaviors, like crashing (sometimes) when the computer comes out of sleep mode. It can also work totally fine on your computer.
The point is, the M1 is not officially supported yet. We rely on a framework called Qt, which is expected to start supporting the M1 around April/March 2021. Once that support is released, we'll soon follow soon after officially releasing a WhatPulse client for the M1.