It shouldn’t unless your mobile carrier is detecting and blocking it for some reason. But, use Session app instead. No email/phone for signup, and your message

It shouldn’t unless your mobile carrier is detecting and blocking it for some reason. But, use Session app instead. No email/phone for signup, and your messages are onion routed through community nodes. Check it out if you haven’t already at getsession.org Alternatively, use a Matrix client with a throwaway email account from Tutanota.