Thanks for the additional information. Are you able to log in to LastPass in a web browser by logging in at https://lastpass.com/?ac=1 or do you see the same prompt for SMS there as well?
Thanks for your message, Rachel. Since I had de-actived the 2-step verification process, of course I didn't get the same prompt for SMS on https://lastpass.com/?ac=1.
What I did now is uninstall LastPass on my phone, restart, redownload, and reactivate the 2-step process, and now FINALLY the problem is resolved.
Thanks for your help Rachel, this is appreciated.