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This causes the available db connection pool to get exhausted and is causing the entire Jira instance to crash.
Workaround
Please consider using Time Reports of Jira Server instead, it has quite same UI, but different backend, so it does not have such problems. See also Comparison Matrix for feature differences.
Solution
Unfortunately, this problem has no clear solution, however Atlassian has confirmed a bug, see JRASERVER-45794 for workaround suggested by Atlassian.
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