Dashboard showing no data for prometheus datasource "wireguard exporter"

This topic has been covered but I have not seen an answer for my specific issue.
I am running a local instance of:

Grafana v8.4.6
Ubuntu server 20.04 LTS
Wireguard exporter
Prometheus to scrape the data from the wireguard exporter
I can curl to both the Wireguard metrics and the Prometheus metrics to confirm that they are both producing data
I created the Prometheus data source in Grafana and it appears working
Imported the wireguard exporter json file for thedashboard

All was working but it just stopped without me changing anything
I have checked and all the metrics are still updating however my dashboard says no data

If I stop the Prometheus service on wireguard server the dashboard gets red exclamation marks, so it appears the data is coming through even my dashboard is saying no data

Can anyone tell me where I could begin to trouble shoot this? I am new to grafana and struggling to troubleshoot the issue.

Thanks in advance for any support.