AutoCAD hangs or pauses when switching between layouts in a drawing. Once AutoCAD recovers, the layout finishes loading. The hang may also occur when switching between different drawings.
A delay when initially switching to a layout can be an expected behavior (see: Short delay when switching to a layout tab the first time in a drawing session in AutoCAD). When subsequent switches to the same layout are slow as well, then it may be necessary to review the contents of the layout.
Layouts in AutoCAD are optimized for a single page/sheet (see Organize Drawings). If Multiple sheets have been created in the same layout or extra geometry exists outside the page area (in paper space), then performance may degrade.
There are instances where modifying specific system variables will improve performance, in other instances it may be necessary to check the drawing for errors and purge unreferenced content.
Does the computer meet the System Requirements for AutoCAD?
Have all available updates* for AutoCAD been installed? Updates can be installed from Autodesk Account or by checking the Autodesk Desktop App.
*Regardless of how long an AutoCAD release has been available, updates to the application will always require a separate install.