Is your mouse creaping around? Sometimes mouselook might take over.
I usually go in the settings portion of DCS and remove all the view controls that I don't want. If you have more than one device doing view, it can get confusing and sometimes the devices compete with each other.
For example, you might have a hat switch on one device competing with another. Or if mouselook is on, moving the mouse may move the view in the cockpit. I have my mouse on a little slant so in that case, if it starts sliding down hill, it would move the view.