lauraneb Hi
To ascertain if peculiar issue relates to specific articles :
1) Have tried assigning default template - Protostar however the issue still persists. Ref: Screenshot
2) Tried assigning another category to similar menu item and the layout appears fine as envisaged with JA Simpli . Ref: Screenshot
Henceforth, The above troubleshooting steps would conclude if the relative issue is not template specific