Yup, definitely a scam. Created a second a/c in my Mycelium, used that. Interesting that the address is verified first - I deliberately put in a typo, and it came up with an address validation error. When I corrected the address, the following came up ...
"You can withdraw your funds only on external address, which is registered and verified with your account. To verify your (external) address with your account, you need to make a deposit from this address. Deposited amount will be added to your current balance amount and will be available for withdrawal at any time immediately. More information you will find on Deposit area in your profile. Minimal amount of the deposit is 0.01 BTC. Current deposit status: 0 / 0.01 BTC. "
Which of course I have no intention of doing.
So, yup, looked like it was indeed too good to be true.
Thanks very much everyone.
This is the most common scam that I have seen. The first time I recieved a message like this in my inbox I knew it would be a scam but went along with it to see if they asked for a deposit before I could withdraw. Now I just ignore these messages. Social media is full of these scammers and they always follow a similar pattern so it is quite easy to identify them. Most of the time they are quickly suspended or shadow banned but they must have some success if they keep attempting it so many times.