I am a new student as well, one week in.

I am in the same boat anytime the chord is more than a one-finger, simple chord. The only way I have been able to overcome it is to practice strumming that chord (A minor in this case) for at least 20 minutes. I play the chord eight times (like in the lesson, 2 four set strums), lift my fingers off the string, place them back on, rinse-wash-repeat. It takes me a bit to find the exact placement of my fingers to get clear notes, but it eventually comes.

The next time I pick up the guitar, I practice all of the chords I have learned so far, and I find it does not take as long to find the groove of placing my fingers.

Repetition, repetition, repetition is the only thing I have found that works! Deep breaths, patience, and a dose of competitiveness help too!