Problems with Sync Sentry Assignment to Jira and vice versa

Hello! We migrated from Sentry 9.x version to the 21.1.0 (486d790).
All works fine and we decided to try integration with Jira cloud.
All options works instead of options with issues assignments ( Sync Sentry Assignment to Jira and Sync Jira Assignment to Sentry).
After changing the assignee parameter to any user in the linked issue we get errors from worker log like this:
sentry.integrations.jira: jira.assignee-not-found (integration_id=# user_id=## issue_key='JIRA-#')
All our users log in via google domain (auth SSO).
Can you please tell me what could be the problem?

any thoughts?

Heya, I filed a new issue and assigned it to the relevant team on GitHub: Problems with Sync Sentry Assignment to Jira and vice versa · Issue #24171 · getsentry/sentry · GitHub

You can track the progress there (and engage with the team for clarification on certain points when/if needed).

Thank you!