I would start by taking a look at your logs to see if there are any specific errors as mentioned above. If you can setup Application links and everything else seems to be going through ok you may want to collect a tcpdump and see what's happening to the traffic.
Hopefully there's something in the logs that indicates what the issue is. Let us know.
Hey Atlassian community, I help lead engineering at Sentry, an open-source error-tracking and monitoring tool that integrates with Jira. We started using Jira Software Cloud internally last year, a...
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