Make cookies: '_pk_id' and '_pk_ses' secure and httpOnly

sorry if this has already been asked before:

trying to set piwik’s cookies:
’_pk_id’ and ‘_pk_ses’ secure (and httpOnly).
Site is https and following options are set in config file:
assume_secure_protocol = 1
force_ssl = 1
it states in the documentation that cookies should be secure automatically (if site is https),
and to to se those values in config if not.

Now nothing is working…