wifi drops and low speeds

on oct 28th they did maintenance for performance issues i didnt have   , now thats all i have speeds gets cut in half ,and wifi drops  at random and not all devices get dropped i can be next to it it drops wifi for my phone but in the back of the house on 5 other devices are fine or the tv gos and all the rest are fine and so on ,i dont expect a fix on here just wanted to make it aware