SLP here. Regarding the initial onset, an interesting and bizarre aspect of childhood onset stuttering is that a sudden severe onset correlates with *higher* likelihood of natural recovery (it's just a "phase"). It can be extremely distressing for families since it comes out of nowhere, as you described, but this is actually better for long-term prognosis vs a mild, slow-building onset. As to the reoccurrence, there is anecdotal discussion about the onset or resurgence of stuttering in conjunction with PANDAS. That would be something to discuss with your pediatrician. PANDAS or not, I would recommend trying to find an SLP who specializes in stuttering. It is an extremely complex and paradoxical experience, and most generalist SLPs do not have the training or knowledge to properly address it. If you're only a month into therapy and the SLP is already "stumped", I would definitely seek at least a consultation with a specialist. Even if you stick with your current SLP, many specialists are happy to provide consulting and guidance to generalist SLPs, and the generalists are usually very happy to have the guidance and learning opportunity! There are excellent resources available from the Stuttering Foundation, National Stuttering Association, and Friends: The Association of Young People Who Stutter.