It's not uncommon for the engine idle speed to increase as the engine temperature rises. This is often a result of the engine control system adjusting the idle speed to compensate for changes in operating conditions.
When the engine is cold, it requires a slightly higher idle speed to ensure proper fuel combustion and to warm up the engine quickly. As the engine temperature rises and reaches its optimal operating temperature, the engine control system may gradually reduce the idle speed to its normal level.
In such cases, it is recommended to have the motorcycle inspected by a qualified mechanic or contact a Honda service center for further assistance and diagnosis.