This has been the same since I started using Upchain a couple years ago, but anyway: with the Solidworks CAD plugin, when you execute an advanced search through the Advanced Search Window, it will generally take a while to complete. An average user with other things to do and multiple screens to utilize will temporarily divert their attention to a web browser or email while the search completes, clicking off onto another window. When the search completes, the user will attempt to resume interacting with the advanced search window, but as soon as they click on it, the window hides behind Solidworks. Hitting Alt-Tab a couple times can recover the window, but this one of the most annoying bugs in the CAD plugin for me.