I have absolutely no clue, never seen that.... but it does sound impossible, UNLESS you may have preferences set to always automatically apply Auto processing to raw images, and your saved raw defaults are also badly screwed up.
Try this once. In ACR on the line below the row of processing tabs, the line that now says the word Basic denoting that the Basic tab is selected ... at the right end of that line is the 3 bar menu symbol. Click that, and at the bottom of its menus, select Reset Camera Raw Defaults. If that improves things, then select there Save New Camera Raw Defaults (to be the new defaults next time).
The problem with the preferences always applying auto actions is that we then never see the original data, so we never realize when we screwed up the camera image, needing that processing. We can always instead manually click the Auto button later if we want it, to apply auto processing then, but first we can see what we actually did first. We ought to realize what we are actually doing. We ought not to imagine we're great photographers if we're not. :)