Are you using persistence with Tails? Or do you recreate the wallet by entering the seed each time?
If you're recreating it each time you run, it's possible that you used a different seed, copied an address from that wallet... and are now "restoring" a different seed/wallet.
If you're using persistence, it's possible you have multiple wallet files and simply copied an address from a different wallet. Click "File -> Open" and see how many wallet files are shown in your "wallets" folder.