Your bag may have been searched at random. TSA does “for cause” bag searches. There may have been something in your bag that triggered a search. In the before time, my bag was opened on 5 consecutive flights.

The TSA (Transportation Security Administration) manually inspects a checked bag if their advanced X-ray or explosive detection systems flag a "questionable object" that the machine cannot definitively identify. According to the TSA, only about 5% of checked bags require this physical search. Triggers often include dense or organic materials that look suspicious on a scan, such as large blocks of cheese, thick books, or tightly packed electronics and bundles of wires, which can mimic the appearance of explosives. Large power banks, lithium batteries (which are actually prohibited in checked bags), and containers of liquids exceeding typical limits can also prompt an inspection. Sometimes, a bag is simply chosen for random selection to ensure the integrity of the screening process. If your bag is searched, the officer is required to place a "Notice of Baggage Inspection" inside so you know it was opened by authorities and not a third party. To minimize these searches, travelers should pack neatly, avoid "overstuffing" bags which makes X-rays harder to read, and ensure they aren't packing any prohibited flammable or hazardous items.