Tooth shifting after Clear Correct limited 12 treatment

Finished 6 months ago. Post-treatment protocol: Bonded wire-4 upper/6 bottom+Clear Correct retainers (based on intraoral scan) are to be worn every night. A few days ago when taking off my retainers, I felt that teeth 12/42 had shifted a bit towards each other, or perhaps only one of them did. it seems odd since I follow the post-treatment protocol (wear retainers, check on the bonding etc) and the clear retainers still fit perfectly. given these facts- could the teeth started proclining? Thx!