In org.ametys.odf.skill.ODFSkillsHelper.createSkillsFromESCOFileCSV(String)

Do not call ObserverHelper#suspendObservationForIndexation, as it will suspend all threads (as a result during this time, any content/page/resource/... added/modified/deleted... is not added/updated/removed in the index)

The right way is to use the mechanism of ObservationManager.addArgumentForEvents and ObservationManager.removeArgumentForEvents