can't become seller due to phone number verification

[femiorukotan]

The step that i can't pass is the verify phone number on fiverr "become  a seller" page, it says somethng is wrong with this number. i used my other family members and it worked(im not using someone else phone as my verification). we're all using the same phone company so i'm confused as to why i can't sign up with my number. this seems like a bug in the system to me, I have a T-mobile sim.