There have been sign-in loop issues with IE for a few weeks, and other problems.

Try this if you're using IE:

tools menu in Internet Explorer, then Compatibility View Settings, add ebay.com.au, ok. The screen will reload and should be OK if you weren't seeing it right/able to do stuff.

If that doesn't work, give Chrome a go as it is more eBay friendly.

This has solved most IE issues recently 🙂