Stunned

You are Incapacitated. You automatically fail Strength and Dexterity saving throws. Attacks against you have Advantage. In the 2024 rules, Stunned alone does not set your Speed to 0.

Duration and overlapping effects

The effect that caused the condition determines its duration, removal, and any saving throws. If several effects impose the same condition, track each duration; its effects do not grow stronger merely because it was imposed more than once. Other conditions can still apply at the same time.

Source: supplied Player’s Handbook (2024), Rules Glossary. Paraphrased quick reference; specific rules can override these general rules.