users will have a few CA PPM tabs open in IE 11 and some additional tabs for other websites. If they close a tab for one of these websites it also closes a tab for CA PPM.
I have searched for past history of this issue, but have not found a match yet.
I'm assuming that only your IE browser is affected by this issue? Any other browsers affected the same way? Are any other web applications besides the PPM app affected the same way?
When did this issue begin to occur? Are all users affected or just some of them? Have the affected users made any changes to their IE 11 browser settings? If so, you might want to try resetting the browser to it's default configuration.
Have you tried clearing your browser cache? Might be worth a shot. Please refer to this communities post for step-by-step instructions for clearing your browser cache.
Hope this is helpful :-)