I had a similar thing happen to me.
Do you have the OOS (out of stock option) enabled?
I do.
I had a food product that expired so I set the quantity to 0.
I'm expecting fresh stock in shortly.
While my listing was sitting there with 0 in stock, showing the old expiration date, ebay cancelled it.
Get this, even f the item is out of stock ebay wants a CURRENT expiration date.
How do you put down an expiration date for a item you dont have???
Because they ended the listing, I had to start from scratch and create a new listing.
This time I had to make up a expiration date until fresh stock comes in.
Crazy.