Packed by a multihead form fill and seal machine. You probably got a bag where all the heads filled low mass, so it could not get a solution in the desired mass range for the pack, so dumped all that were ready to complete the cycle on schedule. It runs multiple weighing hoppers, and fills them from a central feed, then per cycle ( that is the determining factor, all heads that indicate settled and ready are used for the fill cycle in progress while the others are either filling up after release or are in a settle time regime to get a final mass) calculated which heads need release to fit in the desired set point and allowable variation.
Slower machines use a vibratory feeder and a hopper, and use variable feed speed to get a rough fill then a fine fill to desired mass, but then your cycle time is going to be longer as you wait for a feeder to go ready then dump it. The multihead will at any time have 2 cycles in process, the pack being filled and the next pack dropping down the feed tube, with the cycle being fast enough that as the fill reaches the base of the tube a bag is dropping down to relieve it, and then the sealer jaw closes to form the end seals for 2 bags and separates them with a serrated cutter during the seal cycle.
A complex mix of programmable logic, mechanical design, hot metal, rubber feed belts, servo motors ramping up from zero to 100Hz in 5 cycles on a variable speed drive ( and if you have a few of these machines you do common the motor DC bus to them all to save having to use a 1kW brake resistor block per machine) and PID loops which have to all be set up, along with some high resolution mass measurement in a very noisy environment. When they work they work well, but when they sort of work it can be a pain to get them running properly again.
Here is a new base sealer, you can see the parts and operation, though the multihead filler is not shown. Nice machine, hate to think of the price though, but I can get a locally made one for around $20k.
The multihead filler, showing the computer controls and the method of operation. Not chips but friut, but same principle.