I have the mobile app on my phone but when I log into Rover from my computer and try to book someone, I get an error saying that an account already exists with that phone number. Why does it imply that there is a second account?

All the information is duplicated on both the mobile app and when I log into my account from a computer. I only have one email address so I didn't create a different account on my computer. Can someone please help me? I seem to get a larger pool of people when I look on my computer as opposed to using my mobile.