Those were the first things that our guys tried when we saw the problem. Unfortunately, neither helped. Just tried it again and still same issue. Also, to more easily troubleshoot we’ve disabled WP Supercache, but still no resolution.
Also, we just tried disabling all plugins in case there was some incompatibility (and cleared cache several times too) and unfortunately this didn’t help. By the way, we’re using multisite, though I’m not sure that would matter in this case.