Hello,
Thank you for contacting us and sorry for any inconvenience that might have been caused due to that.
Could you please share the full Schema markup that is throwing this error? Please use a service like this to share the code: https://pastebin.com
Looking forward to hearing back from you.
Hello,
I tried replicating your issue here but it seems the Rich Result test accepted my double quote as you can see in my video screencast here: https://i.rankmath.com/gYkJI9
If you prefer, we can further investigate your issue here. There might be another plugin that is in conflict with Rank Math that causing schema issues.
With that said, please do not hesitate to contact us again if you need our assistance with anything else.