My dinner is usually around 6pm, then around 8:30pm I have a scoop of whey protein mixed with water, and at 10:30pm I have some Glutamine just before bed. Is this scoop of protein at 8:30pm going to hurt my cut cycle I'm in?

As long as it fits your daily calorie and macro goals, no it won't hurt your cutting phase...

I'm not sure what your diet consists of but i'm sure 1 scoop of whey will not affect your cutting phase in a negative way.I too am cutting and at approx.8:30 PM I have a scoop of O.N. whey.23 g p,3 g c,1.5 g f.110 cal.Before bed (11:00 or so) I have a scoop of casein in water.20 g p,2g c, 1gf , 90 cal.It hasn't affected me negatively.