Hello out there,

Acknowledgment: This is a dumb question.

A month or so ago I saw an ad banner and whimsically signed up for a free bitcoin mining site, Start Miner. (there are paid options but I used the free one). I know a bit about how mining works, at least in theory.

I created a wallet (actually 2, Coinbase and Blockchain) and submitted my address. Feeling that Coinbase looked like a more secure site and having nothing to lose, I used that wallet.

Coinbase auto changed my address when I tried to withdraw from Start Miner. and I couldn't withdraw BTC from Startminer to either address. It's a tiny amount, just trying to learn things before putting skin in the game, but I can't figure this problem out. When I attempt to withdraw my address changes before I can do so. I know I'll probably need to start over, but please educate me.