What version of the eBay app are you using?
Make sure it is the latest version for your operating system.
Try posting on one of the mobile app boards, and mention what device you are using, the operating system and eBay app version.
https://community.ebay.com/t5/Mobile-App-Android/bd-p/androidapp
https://community.ebay.com/t5/Mobile-App-iOS/bd-p/iosapp
Each board has a pinned link at the top about which operating system versions work with the eBay app.
