Update the standalone-full.xml to specify the value of Content-Security-Policy header,
<response-header name="content-security-policy" header-name="Content-Security-Policy" header-value="default-src 'self';"/>
But the adminUI still returns content-security-policy: frame-ancestors 'self'
Siteminder 12.8.07
It's a known issue on 12.8.07.
The issue fixed on 12.8.08, see 'DE565484' in the release note,
A fix for 12.8.07 is available in ticket DE565484, if needed, open a support ticket to ask for the fix.