Middle mouse button click activates zoom in Remote Desktop

Hello,

For my work setup I am using a MBP as my primary computer while using Remote Desktop to log into a PC to do CAD work (using Solidworks). To rotate a part in Solidworks, you click the middle mouse button an drag. However, whenever I do this, the Windows zoom tool appears. It seems that somehow the PC is getting the key sequence "CMD + '-'" whenever I push the middle mouse button. I can tell that the PC thinks that it is receiving those two keys because if I'm am focused on a text box in the windows virtual machine a '-' character will appear in the box. Additionally, the Windows keyboard shortcut to make the zoom tool appear is "Windows Key (CMD) + '-'"

Also, when using Chrome in OSX, the middle mouse button click also seems to activate the zoom feature.

I have tried looking in all the places I could think of where some hotkey may be activated (OSX mouse and keyboard settings, Windows mouse and keyboard settings, Remote Desktop mouse and keyboard settings) but have not found any solutions.

Could anyone tell me why this is occurring and what I could do to fix it? Is there a way to see what program is catching mouse button presses to see if there is some application causing this to occur?