Lightroom Classic .exe process needs 3 minutes to terminate after main window closes

Hi,

Since this morning, LR has started to misbehave when exiting. No system change. No preference changed. No image added or removed from catalog. No image edited. Just opening LR and browsing in the Library module. An attempt to load another catalog failed and I immediately observed that the lightroom.exe process was still running and the catalog still locked.

Further investigations using Process Monitor showed that after the LR main window closed, the process was still alive for about 3 minutes. After that the process terminates normally or crashes.

Most of this time is spent trying to access .PDB files in C:\Program Files\Adobe\Adobe Lightroom Classic CC, C:\Program Files\Adobe\Adobe Lightroom Classic CC\DLL and C:\Program Files\Adobe\Adobe Lightroom Classic CC\Symbols. The DLL and Symbols subfolders do not exist.

Every Windows developer knows what this means. PDB files are used by debuggers in order to locate errors in the source files. They are never released with the final version. Am I running a debug release of LR ?

I also noted dubious accesses to Amazon servers at amazonaws.com although I'm not syncing.