In testing, we observed that aarch64 cloud instances running in an Openstack instance would hang occasionally, often during disk-intensive operations like software compilation. We observed this on a specific public Openstack cloud (Vexxhost), but cannot be sure whether it is somehow specific to that environment or may also affect others. We did not yet encounter the issue in testing on Amazon EC2.
This issue appears to happen only with btrfs storage, which is the new default in Fedora 35.
Bugzilla report: #2011928