Perhaps the formula of the mask contains more moisturizing ingredients. South Korea's Mediwell Reservoir mask is mainly used for moisturizing, and may contain rich moisturizing ingredients, such as hyaluronic acid and glycerin, which will form a moisturizing film on the skin surface, making the skin feel greasy and sticky.
Maybe your skin's absorption capacity is slow. Everyone's skin absorption capacity is different, and some people may feel greasy and sticky about masks containing more moisturizing ingredients. This is not to say that the mask is not good or suitable for everyone, but that it takes longer for your skin to absorb these moisturizing ingredients.
If you don't do a good job of cleaning before applying the mask, you will also feel greasy and sticky after applying the mask. Because the dirt and grease on the skin will prevent the moisturizing ingredients in the mask from being absorbed by the skin, thus forming a greasy feeling on the face.
Maybe you didn't use the mask correctly. Before use, apply the essence in the package evenly on the mask and then on the face. If the essence is not evenly distributed on the mask, it may cause the mask to feel greasy and sticky on the face.
For the situation you described, I suggest you try the following solutions. Gently wipe off the excess essence on the mask with a cotton swab or cotton pad to reduce the greasy feeling. Make sure the skin is clean before applying the mask. You can use a cleansing product to clean it. You can also try other mask brands that don't contain too many moisturizing ingredients.
Everyone has different feelings about the mask, so a brand or product that suits others may not suit them. Choosing a mask that suits you needs to be decided according to your skin condition and needs. I hope the above suggestions can help you and wish you a healthy and beautiful skin! If you need more advice about the mask, you can also consult a dermatologist or professional beautician.