Hi, from working at a related s390x issue in Ubuntu [1] I can confirm that the recent fixes in nss master resolve this issue. Upstream bug [2], fixes [3][4] If you can't just wait for 3.67 I hope that FYI will help you to fix it.
[1]: https://bugs.launchpad.net/ubuntu/+source/nss/+bug/1931104 [2]: https://bugzilla.mozilla.org/show_bug.cgi?id=1566124 [3]: https://github.com/nss-dev/nss/commit/32ebd26354548fc3f883a56e8bfafc78f5265ce8 [4]: https://github.com/nss-dev/nss/commit/73b47b7cb5133302087980ef321a83670d383db1 -- Christian Ehrhardt Staff Engineer, Ubuntu Server Canonical Ltd