Thank you for getting in touch with us, we do appreciate your time.
If you would like to reset each of your marker icon default URL paths, you may click the “Reset” button for the “Default marker image” setting which can be found in the “Advanced Settings” tab on your Map Editor (Maps -> Maps -> Edit -> Advanced Settings).
If you are wanting to ‘reset’ each of the URL paths for your images in your markers, you will need to manually reselect your image by editing your marker.
Alternatively, you could export all your markers (Maps -> Advanced -> Export) and change all the occurrences of your old domain name with your new domain name. Once this has been done, you may then reimport your markers (Maps -> Advanced -> Import) to your map by using the “Apply import data to” and the “Replace map data” options.
Please do let me know if this helps?
I look forward to hearing back from you.