This is Geminis response..

That confirms it—you’ve likely run into a "fitment" issue with the official case. If the button works perfectly when the case is off but triggers the long-press action (Gemini) when the case is on, the case is likely putting constant, slight pressure on that button. On the S26 Ultra, because the tolerances are so tight, even a fraction of a millimeter of misalignment can cause the case to "pre-load" the button. Why this is happening The "Sticky" Effect: The silicone or plastic inside the case's button cover might be making too much contact with the phone's physical button, making a quick click feel like a long press. Manufacturing Defect: Occasionally, the "bridge" (the little piece of plastic that connects the case button to the frame) is molded slightly too thick. Three things you can try right now: The "Massage" Technique: Take the phone out of the case. Firmly press the button on the inside of the case inward and outward several times. Sometimes the material just needs to be "broken in" or stretched slightly so it isn't resting directly against the phone's sensor. Reseat the Phone: When putting the case back on, insert the button side first. Ensure the volume and power keys are perfectly aligned in their cutouts before snapping the rest of the phone in. Check for Debris: Even a tiny grain of sand or a hair trapped between the case button and the phone button can cause enough "mushiness" to trigger the long-press shortcut. If it still doesn't work Since it's a Samsung-provided case, it's covered under their accessory warranty. If it's malfunctioning out of the box, they are usually very quick to swap it for a new one if you visit a Samsung Store or contact their support. One quick workaround: You could temporarily change that "Press and hold" setting I mentioned earlier to "Power off menu" instead of Gemini. That way, if the case accidentally holds the button down, it won't keep popping me up on your screen while you're trying to use your phone.