Jenkins GUI very slow - fast after browser cache clear

This cookie was causing the slowdown problems in the GUI: ACEGI_SECURITY_HASHED_REMEMBER_ME_COOKIE

When I cleared this cookie (and performed a relogin) Jenkins was very fast again.

It is not a true fix, but for us a decent workaround:

Enabling the "Disable remember me" under Configure Global Security fixed it for us (effectively removing the "Remember me" from the login screen.

Update: This is the Jira ticket regarding this issue:

https://issues.jenkins-ci.org/browse/JENKINS-56243

Quite a few people are having the same problem, and Active Directory does not seem the root cause because people report having the same issue without AD integration. Unfortunately the Jenkins developers do not seem to give it much priority...