I have a Custom races that follows the rules from the Race Building in the ARG. One of the abilities is Climber, which gives a 20' Climb Speed. With that climb speed, the race should also have a +8 modifier to the climb skill. This is reflected in some output sheets, but not all of them. The Standard.html.ftl sheet (the one the Character Sheet tab defaults to), is one such sheet. The Fantasy_Character_Sheet.html works fine however. Now sure where the disconnect is, as I have never looked into the Output Sheets before.
My sheet looks correct. If this is strictly homebrew, then the cause is normally a race being coded incorrectly. MOVE:Climb,20 should work, it sounds like it triggers the +8, so everything is good. Look at the F10 log, chances are you have a bug being reported and it's messing up the export.
Rule of thumb, if you cannot reproduce with release materials, then the problem is not with the program. My test race was an "Adherer".