Field name missing after transformation

Hello. I’m new to Grafana, trying to monitor a few SNMP devices with Prometheus.
I have a metric that comes in like this:

In the time series graph, I want to multiple the serverCPULoad by 100, but when I do that it loses its name:

So when I set Display Name to `${} it looks like this:

How can I preserve the name after transformation?

I’m using Grafana version 10.0.3.