Root_Url unsupported Values

Hi, I have created a plugin and signed it using a private API key. My api_url = http:///grafana and using the same path in root_url. It was working fine in grafana:7.3.6 but after upgrading my grafana to 8.4.5 I am facing an error of Unsupported values error which I think is leading to another error
“Skipping loading plugin due to problem with signature” pluginID=my-panel status=invalid"
Main Error: “Could not find root URL that matches running application URL” plugin=my-panel appUrl=http:///grafana/ rootUrls=“unsupported value type”

I have found the problem. The issue is when npx creates manifest.txt it replaces http:///grafana/ with http://grafana/ which is causing an unsupported value type error. Does anyone know how to make sure that the same URL goes into manifest.txt
Thank you