A few questions... Are you fertilizing? How, how much, when? If you test the soil at a depth of 3 inches and also test as close you can get to the bottom of the pot, does the soil feel: dry, moist or wet? Has it been outside during winter 2023-2024? Is the soil acidic? Are you using a potting mix with well draining, ericaceous soil for azaleas, rhododendrons, camellias or hydrangeas? Meaning, with no garden soil? Does the pot have water drainage holes? Is the area windy?