Cannot post item

Hi

i sold an item recently and the buyer paid I went to print off the postage label to find stuff in red saying address incomplete yet it was there but some lines were in grey. I contacted the buyer who confirmed his address however EBay would not let me edit. We both tried to contact eBay but no help. I read I needed to cancel then relisht. Inform the buyer and ask them to make me an offer for which it should have sold for. Did all this but eBay rejected buyers offer as claimed broke rules and trying to sell outside eBay. The exact opposite is true and it s eBay that created the problem. What can I do do the buyer getting his item and I get paid? Trying to do within the rules but it’s EBay that are forcing and driving me to other options and they lack of help is awfully