Thanks for reaching out. Just to confirm, do you have "Notify subscribers" selected in your advanced settings? Also, mind sharing more info about the Creator Studio glitch and subscriber loss? Keep us posted.
Thanks for the info. Generally, it's normal to see fluctuations in your sub count. This is because we want to make sure the numbers are 100% accurate, so we perform additional verification & spam reviews. Also, it's likely folks are subscribing & unsubscribing as well.