LabPlot stores its settings on Windows in the folder. C:\Users\<user_name>\AppData\Local this does not follow the Windows specifications that requires the folder C:\Users\<user_name>\AppData\Roaming\<program name> see https://www.microsoft.com/en-us/wdsi/help/folder-variables
this is fixed in the latest rc8 package at [1] by patching ksharedconfig.h [1] https://theorie.physik.uni-konstanz.de/gerlach/labplot/labplot-2.5.0rc8-64bit-setup.exe
Many thanks! I'll try to find some time and provide a Win installer.