title: "Invalid Dynamic Link" error page after user uses login link
body: <p>I am using Firebase email login link to authenticate the users of my iOS app, but for some users the system doesn't work and are presented with the following page after they tap on the link sent by Firebase via email:</p>
  
  <p><a href="https://i.stack.imgur.com/6j1pF.png" rel="noreferrer"><img src="https://i.stack.imgur.com/6j1pF.png" alt="enter image description here"></a></p>
  
  <p>This happens sporadically and for a handful of users only, so I haven't been able to reproduce it. Most of my users are able to use the email login link system ok. Having talked to users who have this issue, they don't seem to be doing anything differently from the ones for whom the system works.</p>
  
  <p>Has someone else encountered it and if so how can I solve it?</p>