Specter app not loading; everything else seems fine

Hello, I can’t get into the Specter Desktop app. In the window trying to open Specter, the browser just gives a generic “cannot load page” error. Back in Umbrel’s app page, it just shows Specter as trying to “load” — greyed out, not able to click on it. Umbrel itself loads fine, as does other apps (e.g., Thunderhub). It’s not working in either Safari or Brave, or on my phone (Safari). Any ideas? Thanks.