It works fine for me. It might be something specific to your setup.

You should share your ?-menu’s Debug Info, which might indicate something strange, or at least show if you have a lot of plugins.

Debugging techniques:

You might also try to only pick a subset of the files (maybe doing 4 or 5 of the 6 shown, in various groupings) to determine if it’s one specific file that’s causing it, or if it’s just any time you pick a handful of files and open at the same time, it does this.

If you do have plugins, you could see if disabling them fixes it. You can either rename one or more of the directories in the c:\program files\notepad++\plugins directory to disable them one-at-a-time, or just rename the whole plugins directory to disable all plugins at once. Also, if you know how to change the “Edit with Notepad++” action in your registry using regedit.exe, you could add the command-line option -noPlugin to the right-click action, and see if that speeds it up. If disabling one or more plugins fixes it, then the plugins are your culprit.

If that’s not enough, and you can edit your registry, then trying the -loadingTime command-line argument in your right-click action might show you where the time is going.

Double-checking before posting : I had forgotten the “Edit with Notepad++” was provided by NppShell.dll, so you cannot add a command-line argument to it; sorry. However, if you have registry access, you can still try some experiments: go to HKEY_CURRENT_USER\SOFTWARE\Classes\* and go into the Shell key if it exists (or create it if it doesn’t). Add a new key NppExperiment under Shell, and set the (Default) inside Shell to Open With Notepad++ Experiment. Create command key under NppExperiment. In the command key, set the (Default) to "C:\Program Files\Notepad++\notepad++.exe" -noPlugin -loadingTime "%1" . Once that’s all done, your right click menu (or, if you’re in Win 11, you might have to use Alt+F10 or whatever its shortcut is today for the hidden old-style menu) and select the “Open With Notepad++ Experiment” when multiple files are selected, and see if it’s better (because of -noPlugin) or gives more info (because of -loadingTime)

(Both of those command-line options are described in the User Manual at https://npp-user-manual.org/docs/command-prompt/)