DNA: Why Chinese soldiers object to the birthday celebration of Dalai Lama?

Chinese soldiers and some civilians entered inside "Indian" territory along the Line of Actual Control in ​​Ladakh's Demchok area and objected against the ongoing birthday celebrations of the Dalai Lama. To stop the ceremony, the PLA personnel shouted at the local people and asked them to stop the ceremony. However, the locals remained adamant and the celebrations continued throughout the day.