Child Epics and Issues take a long time to load for deeply nested Epics
Summary
If an Epic is several levels deep within a group, loading its child Issues and Epics when page opens is considerably slow. This was found in https://gitlab.com/groups/gitlab-com/customer-success/professional-services-group/product/-/epics/22 where request to /graphql
for Epics and Issues tab takes ~10 seconds
to complete (even on repeated page visits).