Very slow responses after initial login.

Following messages displayed in the browsers debug page

[Error] Viewport argument key "minimal-ui" not recognized and ignored. (login, line 10)

[Error] Failed to load resource: the server responded with a status of 404 () (lan.css, line 0)

[Error] Failed to load resource: the server responded with a status of 404 () (lan.css, line 0)

[Error] Failed to load resource: the server responded with a status of 404 () (index.umd.min.js.map, line 0)

Accessing this page directly

https://REDACTED/locale/lan-1693964108888/en_US/lan.css

gives

Sorry, the browser is not compatible.

The current browser does not support Omada Controller. Please upgrade to a newer version or use other browsers.

Brower Version 17.1 (17616.2.9.11.9, 17616) (latest)

Please advise.