Profile page header stays on "Loading Profile" when the user isn't found

how to reproduce:

go to flackle.com/app/profile/123 (any user ID that doesn’t exist, or something like /app/profile/abc)

wait for the page to finish loading

expected: the top bar changes once loading is done, e.g. to “Profile” or “User not found” (on your own profile it correctly says “Your Profile”).

actual: the page body shows “User not found” with a “Back to Friends” button, but the top bar keeps saying “Loading Profile” with the user icon. It never updates (still there after 10+ seconds), so the page says it’s loading and not found at the same time.

related: the API call behind this (GET /api/users/by-id/{id}) also returns 500 instead of 404, reported separately.

browser: Brave on Windows 11