Editing skills erases previous skills selection

What's happening?

If I want to add a skill to my profile, my previous skills selection disappears and only the new selected skills are showing up

Steps to reproduce

1. Go to your profile and make sure you already have skills selected
2. Edit the skills and try to add a new skills
3. See that before saving you see all the skills selected - all good
4. Save, the new skill(s) you have tried to add is now your only skill - all previously selected skills are gone

adding wordpress:

after saving:

Your Environment

• Browser name and version: Firefox and Chrome
• Operating System and version (desktop or mobile): both