After upgrading from 2.346.1 to 2.346.2, when loading the Manage Jenkins page, initially there are no warnings about plugins at all (deprecated plugin warnings and security warnings).  After refreshing the page, all the warnings show up.  This consistently happens when logging in for the first time in the day, and the warnings are only not visible on that first view.  Photos attached of the first view and second view. 

Logging out and back in does not seem to recreate the issue; I'm not sure when it resets itself, but this has happened for two days in a row when logging in for the first time. It also seems to be server-side, as I can log into my account from a second machine and can't reproduce the issue, it's only after a time delay that the issue comes back, and only the very first time that page is viewed.