iPhone won’t call a certain number

Hi there, Shorty098!
Thanks for reaching out to the Apple Support Communities! It sounds like you are having an issue calling a specific phone number and I am happy to help! You have tried great steps checking if the number is blocked and being sure Do Not Disturb and Airplane Mode are not on. If you have ensured the other party has not blocked your phone number by mistake on their side, I recommend taking a look at this article with steps to follow If you can't make or receive calls on your iPhone. This article will give you the best additional steps to take along with what to do if you continue to have issues making a call to that number.
Cheers!

If you're having a problem reaching one specific number, and they have not blocked you, contact your cellular carrier. It's probably a routing problem in the cellular network.