During my short sprint training during my plyo sessions, I get discomfort/pain in my groins.
Is there an explanation for this and anything I can do to prevent this?
My explanation would probably be that you're not getting adequate glute activation, and/or your hip mobility is too poor in someway.
The first thing I would do is get some massage/SMR done on your adductors, given that you haven't torn anything, it'll help with alleviating pain, as well as improving likely poor tissue quality. You can do this with your hands/foam roller/barbell. The hands and foam roller will be less painful, and the barbell will definitely hurt the most(so work up to it slowly if you're going to do it).
Following up your soft tissue work, I would look at the positioning of your pelvis. If you have excessive anterior pelvic tilt or hyperlordosis, I would consider some rectus femoris stretches/hip flexor stretches. Too much tilting will put undue stress on your hamstring muscles(in your case, medial hamstring, I would assume).
Once you've done that, improving your general ability to flex the hip would be nice. That is, work on hip flexion with the knee extended, hip flexion with hip external rotation, and hip flexion with adduction. That should cover all your bases.
In terms of your training, you should look at your style of squat. Styles that point the toes out, like low bar Rippetoe squats, will tend to recruit the medial chain more(and thus adductors). HOWEVER, even high bar squats can make you sore in the adductors, so you don't necessarily want to just change your style of squatting. This is just an indicator that you need to improve your mobility/motor control.
Also, try posting a video of you doing some sprints, you might be overstriding as well. Multiple camera angles would be nice(front view and side view).
