I am not sure if we have enough detail to answer however ..... Check Labor rates . Labor rates i beleive have a property that if none are set - use 50 dollars an hour - check that property maybe its unchecked - also in additon to that Labor Rates - if not set up already for the users should be set up - Because in the case there were no labor rates set and that property was set to 0 all cost would be 0.
Also Timecards generate expense lines - So check if there is an expense line associated to the approved timecard - see what the value is for cost - Also then see if the expense line is PROCESSED - typically expense lines are processed nightly - so if that was the first time you ever did it in the screenshot maybe the next day the costs showed up. There may be more possible explanations like scripts affecting this . Also one last thing, if these timecards were imported in or backdated to previous months they wont update the previous fiscal periods - the trick for that is to toggle ONE expense line from that month to pending and back to processed then it will do the math and count all of the values for that month.
If some of my possible answers seem like they are going in another direction then please disregard but these are reasons and solutions i have seen for a variety of issues like this.
