Microsoft Teams - downloading a file from within a

Question

I've created a configurable tab app and have side-loaded it into Teams. On the content page, I want to allow the user to download a file. Simply linking to the file doesn't work. When the user clicks the link, the content iframe redirects and goes blank. I've tested this in the web app version of Teams at teams.microsoft.com and it works fine. The file gets downloaded as you would expect.

If it makes any difference, the content page is hosted in SharePoint on a modern page using SPFx.