This is my unofficial understanding that I hope will help you.
At Panther, there isn't a "check in call" when arriving to a board. Your satellite ping is what determines your arrival.
Second, with regards to losing board position because you are parked in a garage.
Qual-comm employs more than one satellite. You may be on one at arrival, but as the day progresses and it switches to the next, it can't obtain a location on you. After a prescribed period of time when the next picks up your truck it is time stamped.
Through the duration of time that it couldn't locate your truck and other trucks came onto your board with their times, they went ahead of you. Sometimes this can be witnessed when you are sitting in a location and at some point you lose your QC signal even though you haven't moved the truck.
Remedy
Do a macro 32 or 8 upon arrival in order to time stamp your location on that board. One can check via the Internet the board position and if anything is in question, call contractor relations. It is a quick fix for reinstatement of position if they have a time stamp with you on that board.
Lastly, when they send you a load, they may not always call right away. That is driven by the call and load volume. Sometimes many loads come in all at once. They will prioritize the earliest pickups first. Some loads are within a couple of hours while others may be 12 hours away. Thus the introduction of the text messaging. If a load sits on your qc for a extended period, it is because it isn't covered and doesn't have the same time restraints as what they are working on. Or....they just plain dropped the ball.
One more thing of note. The original dispatch program would circle a mile radius from the customer. As of roughly 30 days ago, it now revolves based on a percentage of DH miles against the loaded miles.
Hopefully that helps. If not, feel free to send me a email or PM.