2 exact missions one month apart, 2 totally different quality of image

I don't see any maps in your email address's account that match these dates. Creating more than one account is generally frowned upon... 

Reasons for differences in processing are generally overlap related but could also be due to different lighting conditions or processing settings. 

Also, if something is near the edge of the map and gets less overlap it can turn out very differently than if it were more central to the survey area. 

Generally rerunning the same data the same way will not yield different results. You may get different results if you run it with different settings. 

Sorry, did not meant to create a 2nd account, I guess I used my Google account to create the Zendesk account. Not done intentionally.

The images look like they were taken at different times of day, with different lighting. Deep shadows in Jan, not much shadow in Feb. Did you process these prior to uploading to MME?