A little late, but I ran into this issue and manually updated the property names to match what is required for Ignition.
For example, I changed:
"properties": {
"stroke": "#0f3df5"
},
To:
"styleOptions": {
"color": "#0f3df5"
},
However, I found the section in the Ignition Docs that walks through the process of Adding GeoJSON Shapes. Following these instructions will expedite the process.
Also, here is a related forum post, Importing KMS/KML data into ignition perspective Map using GeoJSON property