I saw that both of your events this year had only 5 teams.
I’ve heard the minimum number for a VEX U event to be official is 6, so maybe the event where you got a Programming Skills score was removed from the World Skills Rankings due to the low number of teams.
If so, I don’t know why the second event would be listed but not the first, but maybe it’s because the second one was more recent (or maybe Texas treats events with too few teams differently than Arkansas does).
The two scores have to be from the same event for them to be combined. You cannot have a programming skills score from one event combined with a driver skills score from another event.
To clarify, @SkinnyPanda Robotics did get a combined score of 64 twice, but the World Skills Rankings no longer list the first one as having occurred.
According to VexDB:
On December 2nd (in Little Rock, Arkansas), PANDA got a score of 64: 52 driver + 12 programming.
On February 24th (in Friendswood, Texas), PANDA got another score of 64, but this one was 64 driver with no programming attempts.
Both events had only five teams.
Currently, the World Skills Rankings lists PANDA’s highest Programming Skills score from any event as zero (the score from Feb 24), as if the December 2nd event never happened.
My guess is that the Texas event (Feb 24) is being counted as official, but the Arkansas event (Dec 2) is not.
Could have read it at the top of the page showing the skills scores on robotevents.com.
"Global Standings
Standings for the 2017-2018 VEX Robotics Competition ranked season only includes results from official VEX Robotics Competition events.
The column labeled “Score” represents the highest Robot Skills score posted to date, and is used to rank teams.
The columns labeled “Programming Skills” and “Driver Skills” represent the individual scores that comprise the teams highest Robot Skills score.
The columns labeled “Highest Programming Skills” and “Highest Driver Skills” represent the highest individual scores in each category, these are used as tie-breakers per the official game manual."