I am an Indian national living in the UK travelling to Namibia via Frankfurt (along with a return trip). I am flying with Lufthansa through and through under one ticket. My London-Frankfurt flight lands in Terminal 1 at Gate B47 (or any other B gate) and my connecting flight to Windhoek is from Terminal 1 Gate C14 (or any other C gate) - will I need to pass immigration? I ask because I thought this was the airside transit zone but on the digital airport map I see an immigration symbol on the way there.
Thank you!
P.S. I am aware that I need a transit visa however I have a valid U.S. visa which counts for exemption, but I assumed I would not have to pass immigration.