HONG KONG/SHANGHAI—Chinese property shares fell on Monday, as Beijing pushed ahead with plans for a property tax and amid fresh signs of weakening in the real estate market. Chinese developer Kaisa Group’s coupon payment for a dollar bond and the central bank’s efforts to calm nerves over China Evergrande Group’s debt woes, helped in part to offset the overall bearish mood in the property sector. The CSI300 Real Estate Index, which tracks China’s biggest developers, fell 2.6 percent. Hong Kong property shares fared a bit better, with an index tracking mainland property firms trading flat. Chinese regime leader Xi Jinping, on Friday, called for the country to “vigorously and steadily advance” legislation for a property tax, which could curb rampant speculation, according to an essay in the ruling Communist Party journal Qiushi. Rocky Fan, economist at Sealand Securities, said property tax expectations are negative for real estate shares because “people would …