This does not happen in Minecraft Forge 15.2, 16.2... Host computer runs Windows 10. The primary plugged in mouse has no problems. However, when the host mouse is "captured" by the game streaming software I am using (Rainway), then mouse inputs are corrupted. Basically, the movement of the mouse is much exaggerated, and it ends up spinning stuck looking up at the sky or down at the ground. Same thing happens with Forge 1.7.10 which I tested. I also tested Forge 15.2 and 16.2 and this does not happen.