Air Carrier Ramp personnel reported an inaccurate Dangerous Goods cargo load due to late connecting bags and aircraft mechanical issue. Dangerous Goods cargo issues were corrected prior to departure.

Narrative

I got a call on my cell phone from [name] that I had assigned flight X/ZZZ . I let him know that there was nothing on my device and also show him that it was on my device. At this time I had to find my crew for the flight. When I first got to the flight I found out that the bypass pin was broken so my crew could not connect the towbar and push tractor. I call on the radio for a bypass pin and [name] call my cell phone to let [equipment clerk] know that she had given the equipment room an extra bypass pin. I go to the equipment room for bypass pin when I got there the equipment clerk told that she had already given it out. I let [name] know that it was already given out and she said that [name] was on his a way with a bypass pin to my flight. We began to load the flight with 39 mins left before departure. We quickly loaded the forward [cargo compartment] first starting with F2 [compartment] with the freight (1150) and then F1 [compartment] with 38 bags and 3 pieces of pps and two which were DG. Once we finished the forward cargo we move to the back AFT and quickly starting loading in A1 with 42 bags and to A2 with 17 bags. At this time I found out we were missing 17 bags from two flights. I then I let [name] know that they were missing. Then [name] got on the phone and call to see if the bags were going to make the flight when he finish talking he let me know that they was not going to make it. Then [name] called over radio asking me to wait 5 mins for 1 bag come to the flight. Once the bags didn't show up [name] told me to wait because he saw a driver coming. It turned out that it was not the bag for this flight and he told me go ahead and lock up the flight. We lock up flight and when I got ready to finalize the flight I notice that only 1 DG item was showing in the device; there were actually 2 [loaded on aircraft]. I came to the training room to get help correcting fixing this. After error was corrected I try to finalize the flight. I got error message that I have never seen before. The trainer recognized this message meaning that aircraft was out of balance and I needed to call [load control]. I call [load control] and told them the message I was seeing. She ask me what happen and I told her that 17 bags didn't make the flight. She said that she had to talk to her supervisor and put me on hold. After several minutes notice I was not on hold and immediately call them back. When I called them back she said she needed to talk to my manager because they had to move three passenger from first class to coach and put back on hold for several mins. After several more mins load agent came back and told me to try to finalize the flight. I made the entry and the flight finalized.This event occurred for several reasons. the first was a common one; the device never displayed this assignment. When it was assigned to me; which forced a modification to come to me and notify me of it. By the time I was told of this assignment there was only 45 minutes to departure. this is a common problem with the device program and management has been aware of this since the program was rolled out. It needs to be addressed and fixed so we get our assignments in a timely manner. Second; lack of equipment is also a common problem here as well as OTS equipment being issued to us in our equipment box needs to be a addressed and correct these things that take precious time to replace. Our requests for help with this has gone unanswered.