This is actually completely normal. I had a conversation with my child’s slp about this and she said it’s really common for this to happen and that even people who stutter can do it when they spend a lot of time with others who stutter. For instance maybe you typically don’t have blocks and spend time with someone who does and then find yourself suddenly stuttering like that for a bit. It just happens. Don’t take on added guilt or blame for it. That doesn’t help anything, nor is it useful. Although I know that’s easier said than done.