Useful information:

Minecraft version: 1.14.4
Forge version: 28.1.8
CC:T version: 1.84.1
Reproduction:

When in Advanced Computer, no mouse_scroll events register. Tried with lua prompt and a simple
while true do print( os.pullEvent() ) end

Same applies to the Advanced Turtle, but additionally here the mouse_drag doesn't register, either. (In this case I'm not sure if this is supposed to be a new limitation for turtles, just getting back to CC after OC now).

Attached is a link to a GIF for the mouse drag (you just have to believe me I'm keeping the button pressed)
Mouse Drag not registering