What is the reason for the loss of spiritual pleasure that was present in Ramadan previously?

The month of Ramadan is a month of worship, and engaging in acts of obedience with sincerity therein increases faith, bequeaths tranquility, and the sweetness of worship. Neglecting this makes it like any other day. The weakness in engaging in worship during Ramadan might be due to tribulations (fitan). Therefore, it is advised to accompany the righteous, distance oneself from tribulations, and frequently recite the supplication: "O Allah, Turner of hearts, keep my heart firm upon Your religion." It must also be known that the believer worships Allah and is mindful of Him at all times, not just during Ramadan.