Why do some electronics say NOT to use rechargeable batteries when you have tried them and they work?

Some electronics specify not to use rechargeable batteries because they often deliver a lower voltage compared to standard alkaline batteries, which can lead to performance issues or malfunctions in devices designed for higher voltage. Additionally, rechargeable batteries may have different discharge characteristics, potentially causing the device to behave unpredictably. Manufacturers may also want to avoid potential damage or warranty issues that could arise from using batteries not recommended for their devices.