A simple solution is at the bottom of this article.
For more insight, please read the following.
The most common reasons for the Feedback Link not to work is based on mobile usage. One of these three situations might be the cause:
The buyer is using the eBay Mobile app and tries to open the link with the app.
Or, the buyer copies the link into a different mobile browser but is not signed into eBay.
eBay is having compatibility issues with feedback links on mobile.
Insight: eBay's Mobile app browser currently does not support links to other pages on eBay (Android and iPhone). It is circulating around eBay Community forums that eBay may fix this soon.
While we wait for the resolution, in order for the buyer to use the link, they may
need to sign into eBay on a different mobile web browser, then, copy/paste the link into the browser.
Use the official "leave feedback" process in the mobile app.
Solution:
Use this template to explain to you buyer about leaving feedback with mobile.
Leave feedback on desktop PC: {item_feedback_link}
If using mobile eBay, go to Purchase history, select this item, and click "Leave Feedback"
If you have any questions, feel free to reach out to us at [email protected]