Thank you for providing the sources. Looks like you were right (except the few days part). It only affect a subset of users which explains why it went unnoticed

Thank you for providing the sources. Looks like you were right (except the few days part). It only affect a subset of users which explains why it went unnoticed for me. May have been related to the transition of Hotmail accounts but regardless if it keeps happening on a regular basis, I may have to find another provider.