verification codes wont work

I bought a new iphone and the verification notifications have been weird - they pop up with my location for a second, and then disappear without giving me a verification code. I saw I could generate one from my ipad (also on the account) and did so but those verification codes are not being accepted - the code and Apple ID verification code request screen are stuck on the front of the iphone and in the background the AppleID verification screen has a spinning icon at the bottom. All my devices are updated. I tried plugging into my MAC but I don’t have Itunes and plugging in did nothing except prompt me to backup photos. I also tried using my Recovery Key but the phone would not accept that. Although my SIM card is in the phone, I am not getting the Verification code texts.