CSS rendering issue on swissmemorial.ch review (unexpected arrows / overlay issues)

In our BugSmash review for swissmemorial.ch, CSS seems to be interpreted incorrectly: unexpected arrow elements appear (e.g., near images/footer) and overlays look wrong.

We only use .htaccess (HTTP auth)—no firewall/proxy. Could the scan/capture be affected by the login prompt?

Review link: https://hhomepage.bugsmash.io/review/qNxdb