Hi, when you say that your SOT (Screen on Time) has gone down, can you share the SOT after trying the below:
1. Charge the battery to 100% & use as per your normal usage pattern
2. When the battery strength reaches 10%, go to settings = Battery => Tap on the battery icon & share the graph
3. settings => Battery => Check the screen & share the same
Also, kindly share with us the firmware version of the device.