Another user recently found delays when right-clicking which went away after blocking the iCloud extension:
A Process Monitor log of what happens when right-clicking (when the problem happens) could be useful to use in working out what's going on and if we can change something on our side to fix it.
Adding {85527100-19D0-45AF-9F09-DAB4E711C35E} to Preferences / Miscellaneous / Advanced, ignore_context_menus should prevent the problem, if it's the same as the other user saw.
