existing category non listed

Hello. Thanks for the free version of Jevents i'm using.
Sometimes ago I created an event categry i named Dir-école (01.png image attached).
I added some events in this category (02.png image attached).
I noticed some days ago that when i try to edit an event form this category, this event has no category (03.png image attached).
I cannot add this event to the catory i named Dir-école. (04.png image attached).
If i want to add a new event in this category, I have no other choice to make a copy of an old one, add this new event in another existing category, get into my phpadmin database, change the category ID into the id of the Dir-école category.

Below are the technical info of my system :

PHP Version : 7.2.23

MySQL Version : 5.5.5-10.1.37-MariaDB

Server Information : Linux box19.domaineinternet.ca 3.10.0-962.3.2.lve1.5.25.10.el7.x86_64 #1 SMP Wed May 29 04:37:40 EDT 2019 x86_64

Fix jQuery? : Yes

Load JEvents Bootstrap CSS? : Yes

Club code set? : No  

User Agent : Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:69.0) Gecko/20100101 Firefox/69.0  

Joomla : 3.9.12

component_com_jevents : 3.4.50

component_com_jce : 2.7.17

component_com_acymailing : 5.10.4

module_mod_acymailing : 3.7.0

module_mod_jevents_cal : 3.4.50

module_mod_jevents_custom : 3.4.50

module_mod_jevents_filter : 3.4.50

module_mod_jevents_latest : 3.4.50

module_mod_jevents_legend : 3.4.50

module_mod_jevents_switchview : 3.4.50

plugin_acymailing_contentplugin : 3.7.0 (not enabled)

plugin_acymailing_managetext : 1.0.0

plugin_acymailing_online : 3.7.0

plugin_acymailing_share : 1.0.0

plugin_acymailing_stats : 3.7.0

plugin_acymailing_tablecontents : 1.0.0

plugin_acymailing_tagcontent : 3.7.0

plugin_acymailing_tagsubscriber : 5.10.4

plugin_acymailing_tagsubscription : 5.10.4

plugin_acymailing_tagtime : 5.10.4

plugin_acymailing_taguser : 5.10.4

plugin_acymailing_template : 5.10.4

plugin_content_jevents : 3.4.50

plugin_editors_acyeditor : 5.10.4

plugin_finder_jevents : 3.4.50 (not enabled)

plugin_installer_jeventsinstaller : 3.4.50 (not enabled)

plugin_search_eventsearch : 3.4.50 (not enabled)

plugin_system_gwejson : 3.4.50