Linux: After changing ulimit settings the proc limits do not match
When changing the ulimit settings in /etc/security/limits.conf or in /etc/security/limits.d/filename for a specific user, you will only see the correct change in /proc/[pid]/limits if you are looking as the user the limit was set for. Looking at this setting in /proc as root or su will display the settings for root not the user you set within the file.
ulimit -a username
is the best way to tell if the limits config file change is active.