Hello,
We apologize for the issue you are facing with using a special character in your keyword. Rank Math has certain restrictions on keywords, and if it does not accept a keyword with a special character, it may limit your ability to optimize for that specific term.
Using a keyword without the special character could potentially affect your search visibility if users are searching for the product name exactly as it is, including the special character. However, you might consider using a variation of the keyword that excludes the special character or includes relevant keywords that describe the product effectively.
If you have further questions or need assistance with this issue, please feel free to reply to this ticket, and a human agent from the Rank Math Support team will assist you further. Thank you for raising this concern!
Hello,
Thank you for contacting us and sorry for any inconvenience that might have been caused due to that.
We used the same keyword on our end and we can see the tests are getting passed without any issues:

Please note that Rank Math looks for the exact match of your keyword to pass the tests. In this case, please try to copy the exact keyword and use this on your title, description and content and see if that works for you.
Let us know how it goes. Looking forward to helping you.
Thank you.
Hello,
Since we did not hear back from you for 15 days, we are assuming that you found the solution. We are closing this support ticket.
If you still need assistance or any other help, please feel free to open a new support ticket, and we will be more than happy to assist.
Thank you.