Invalid Accept-Encoding header can cause Apache Traffic Server to fail cache lookup and force forwarding requests. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.10, from 9.0.0 through 9.2.4. Users are recommended to upgrade to version 8.1.11 or 9.2.5, which fixes the issue.
https://lists.apache.org/thread/c4mcmpblgl8kkmyt56t23543gp8v56m0