You could try going through your email and delete all old magic links. Some email like gmail have some sort of “nesting” structure for emails from the same address which can make it difficult to determine the current one. Once done that delete the app cache and storage and try re-requesting a new link.
Other than that, I would check that the date and time on your device are correct.
If that doesn’t work then you would need go back to Freetrade support to try and resolve it.