Does the body retain more/less/not at all during combination weight training & cardio versus cardio only? Been struggling off and on with weight stalls/slow downs on the scale and was curious if my exercise routine may be to blame.

Oh the dreaded stalls. I retain more with weight training & cardio. If I just do cardio, I have not problem losing.

I think it is because we are gaining muscle. Our bodies hold onto water more to help heal and rejuvenate the muscles. By sticking with my current workout style, I have stalled a lot. Fluctuating between 3 - 5 lbs. On only cardio days, I lose a lot of weight but on weight training days, I gain that weight back.

I have stopped focusing on my scale at this point and have been focusing on the inches and fat loss. I see a huge change in my body, flexibility, mobility, strength, and stamina.

I'm not sure what you mean by retain in this context. You should be losing water through either strength training or cardio, but obviously you are going to sweat much more during cardio because you will have a higher heart rate and blood pressure increase. This means you need to stay extra vigilant about drinking while you workout.

Working out on the other hand (either cardio or weight training) shouldn't cause you to stop losing weight. Of course cardio may cause you to burn more calories and lose quicker.