Integrations with JIRA and splunk failing sentry 21.4

Having issues with integrating with my jira and splunk instances. @BYK
both apps are accessible via my sentry host . But still getting connection_error from sentry

 | 21:06:53 [ERROR] sentry_sdk.errors: Internal error in sentry_sdk
web_1                                       | 21:06:54 [INFO] sentry.integrations.client: integration.http_response (integration='jira_server_setup' status_string='connection_error' error="SafeHTTPSConnectionPool(host='jira', port=443): Max retries exceeded with url: /plugins/servlet/oauth/request-token (Caused by NewConnectionError('<sentry.net.http.SafeHTTPSConnection object at 0x7f3010194198>: Failed to establish a new co")
web_1                                       | 21:06:54 [INFO] sentry.integrations.jira_server: identity.jira-server.request-token (url='https://jira' error=ApiHostError('Unable to reach host: jira',))
web_1                                       | 21:06:54 [ERROR] sentry.integration.jira_server: pipeline error (organization_id=1 provider='jira_server' error='Could not fetch a request token from Jira. Unable to reach host: jira')
nginx_1                                     | 17.149.238.227 - - [31/Mar/2021:21:06:54 +0000] "POST /organizations/retailtech/integrations/jira_server/setup/ HTTP/1.1" 200 7306 "https://rsentry/organizations/retailtech/integrations/jira_server/setup/" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.90 Safari/537.36" "-"
web_1                                       | 21:06:54 [INFO] sentry.superuser: superuser.request (url='https://rsentry/api/0/organizations/retailtech/?detailed=0' method='GET' ip_address='17.149.238.227' user_id=1)
web_1                                       | 21:06:54 [INFO] sentry.superuser: superuser.request (url='https://rsentry/api/0/organizations/retailtech/teams/' method='GET' ip_address='17.149.238.227' user_id=1)
web_1                                       | 21:06:54 [INFO] sentry.superuser: superuser.request (url='https://rsentry/api/0/organizations/retailtech/projects/?all_projects=1&collapse=latestDeploys' method='GET' ip_address='17.149.238.227' user_id=1)
nginx_1                                     | 17.149.238.227 - - [31/Mar/2021:21:06:55 +0000] "GET /api/0/organizations/retailtech/?detailed=0 HTTP/1.1" 200 6592 "https://rsentry/organizations/retailtech/integrations/jira_server/setup/" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.90 Safari/537.36" "-"