It is true. I never ever use qr code when storing 2FA secret codes. I'd rather use the code itself and write on a paper for example or store it on a flash drives then you can keep it safe from leaking. It seems you are using google authenticator. Is it because where you can sync your account from the current device to other device which in my opinion is good but it also have disadvantage where the company that create that platform may have access to your credentials which is bad. I have been using google auth and Authy for 2 years.