clear filter hanging some times

we discovered a strange behavior today: First depending from the actual user only subsets of incident where displayed in the incident list. To be sure that all available row are displayed, we refreshed the view and cleared the filter more than once. Nothing happened, as if some user have only access to some incident depending from their role. Then we added a additional filter and repeated the "clear filter", finally  all the rows where displayed:

As if the Clear filter function is sometimes blocked, does nothing, and the work around would be to add a filter criteria, independant of the fact if before any filter has been set. Any idea?