Toolbar slow on Raspberry Pi 1B and 3B (Docker/Alpine)

Just to confirm, that property is baseURL, not baseUrl.

But you did set in app/Config/App.php. A setting mistake is not likely to happen.

Do you see the debug toolbar?

I confirm it is correctly set (and this is confirmed by the fact that my links created with base_url() change accordingly) .

The debug toolbar is correctly displayed as well, but with very long time, as mentionned.