It might be the case that you have environment variables set:
The final creation of a Git commit object is usually done by
git-commit-tree, which uses these environment variables as its primary
source of information, falling back to configuration values only if
these aren’t present.
GIT_AUTHOR_NAME is the human-readable name in the “author” field.
GIT_AUTHOR_EMAIL is the email for the “author” field.
GIT_AUTHOR_DATE is the timestamp used for the “author” field.
GIT_COMMITTER_NAME sets the human name for the “committer” field.
GIT_COMMITTER_EMAIL is the email address for the “committer” field.
GIT_COMMITTER_DATE is used for the timestamp in the “committer” field.
EMAIL is the fallback email address in case the user.email
configuration value isn’t set. If this isn’t set, Git falls back to
the system user and host names.
It might be the case that you have environment variables set:
The final creation of a Git commit object is usually done by git-commit-tree, which uses these environment variables as its primary source of information, falling back to configuration values only if these aren’t present.
GIT_AUTHOR_NAME is the human-readable name in the “author” field.
GIT_AUTHOR_EMAIL is the email for the “author” field.
GIT_AUTHOR_DATE is the timestamp used for the “author” field.
GIT_COMMITTER_NAME sets the human name for the “committer” field.
GIT_COMMITTER_EMAIL is the email address for the “committer” field.
GIT_COMMITTER_DATE is used for the timestamp in the “committer” field.
EMAIL is the fallback email address in case the user.email configuration value isn’t set. If this isn’t set, Git falls back to the system user and host names.
Source: https://git-scm.com/book/en/v2/Git-Internals-Environment-Variables