As of December 1, 2020, European Instagram users can no longer view the number of replies to their stories posted. It's been the same for users in Japan since April 14, 2021
This decision follows the application of new regulations on the protection of personal data in these regions (GDPR in Europe).
Indeed, replies to stories are private messages that users can send to content creators in reaction to their stories. They are therefore excluded from account statistics.
Replies to stories made by European and Japanese users are also deducted from the story statistics of other users' accounts.