Mandatory Field Validation Issue for Custom Blog Categories

I have a custom blog category on my site with mandatory description fields. Whenever I attempt to create a new blog category entry, entering just the title (without filling out the description fields), the system allows me to save the entry without any alerts for the missing data. The title gets stored, but the category is created with blank description fields.

On the other hand, if I fill out some (but not all) of the mandatory description fields and try to save, the system again permits saving without warnings. However, in this case, none of the partially filled description data is stored – only the title remains.

Could you please explain why the mandatory field validation seems to be inconsistent and not working as expected? I need to ensure that all required fields are properly populated before a new blog category entry can be saved.