Changed phone, same sim and number, can’t login

Hi there

I’ve just changed my phone but kept same SIM card, same number, transferred all data and apps from old phone. All apps working fine on new phone except Telegram.

When I try to sign in it asks for my number. I type it in and it says: “We have sent the code to your Telegram app to your other device”. I don’t have another device. Does it mean my old phone? All the data has been wiped from that phone, and it no longer has the old sim or number. What other device does it mean?

I really need to login into Telegram. I have a lot of work contacts on there!

Cheers