I see you posted this in the very early hours here in the UK this is the time eBay HQ tweak and update in CaliforniA so temporary site glitches may occur.
Or, it could be the device you are using or browser? I don't use the app, but believe a new update needs to be installed. Or switch browsers, Chrome and Firefox work well with eBay.
The classic cure of clear cache and cookies may help too.
@1teletom7