Im this way too! During summer my speech gets way worse. Im now over 20 yrs old, and Ive diagnosed the reason for this to be that during school years my mind and body got so used to the rhytm of school stopping and summer holiday starting (i live in a country where we get 2 months Off from school every summer). During summer break I could finally just relax and be me with my family without masking of any sort, so my stutter got worse. OR that my family was so anxiety inducing that being with only them for 2 months and no school was too traumatic for my small little brain back then 👀🤷 Who knows, really just my thoughts from years of wondering. Then when "schools start" (even tho Ive been working full time for multiple years) at the end of July start of August, my speech is okay again 😅 its like clockwork.