F15 5g which phone you are talking about? (But let me clear you one thing i charge my phone in super fast charging with a local charger not samsung charger) maybe this can also be a reason of battery draining
One ui 6 was far much better than one ui 7 and one ui 8 on one ui 6 my phone battery backup was almost 13 hours with in heavy use but in one ui 7 its only decreased to 7 hours approximately
