What’s happening here depends a bit on your settings TexturePacker.
TexturePacker comes with a built-in anchor point editor. To use it you have to use the cocos2d-x exporter.
There’s “Enable pivot points” in the right sidebar. If this is enabled the anchor points are overwritten with the values from the plist file.
So you should be able to either use the editor to set the anchors - or disable it in TexturePacker.