whys my serum coming off?

hello, anytime ive been using serum for my skin these few days it keeps drying up and coming off like this? i dont understand why, is it because of the serum im using? is it because i use cicaplast la roche posat B5+ every night? i have multiple types of serums i use for moisturizing cuz i use panoxyl everyday, my skin isnt clear but its not the worst either, its not dry or oily its just normal so i try to have a basic skincare routine and this has been happening for a bit, i dont understand why that is