Detect Isolated Unconnected Vias Warnings

I have a problem with the DFM analysis reporting warnings from the "Detect Isolated Unconnected Vias" check. There are four vias on my board connecting the ground pads on the top layer, to a ground plane on the bottom layer. The vias and the bottom ground plane are all members of the GND net. All the DRC rules pass in my design software (Kicad) but when I export the Gerber and run through JLCDFM I get the warnings. What am I doing wrong, how can I clear these errors in DFM? Screenshots of top, bottom and warnings below. Thank you.

Top Copper:

Bottom Copper:

Unconnected Vias Warnings: