Why did the set (Promoted Listings Advanced) Negative Keywords disappear inexplicably?

[beyond21inc]

Why did the set (Promoted Listings Advanced) Negative Keywords disappear inexplicably?

I got few messages from ebay ,and I did fill some negative keywords ,But I just found all of negative keywords were disappear today ,What happened ?

[adsteam@ebay]

Hello @beyond21inc ,

We confirmed that there were no issues that were introduced as part of our recent negative keywords update. We suggest you contact eBay Customer Service who can help with adding negative keywords to your Promoted Listings Advanced campaigns.