Hi There,
Thank you so much for getting in touch with us, and our sincere apologies for the inconvenience.
This is supported with our latest versions by navigating to Maps -> Edit -> VGM -> Scroll down to “Allow users to select a marker category?” -> Please enable this option.
The categories should now display in the VGM form.
If this issue persists, could you please confirm the WP Google Maps Pro and VGM version installed on your site?
I hope this helps clarify, I look forward to hearing back from you.
Kind Regards,
Abel