Mixing up agar plates

Hey guys, Microbiology tech here. My lab has had an influx of issues regarding the mix up of red colored agar plates (BAP, CNA, CDC, etc). Our plates are kept in stacks at our inoculation bench, and it seems that plates are often just placed in the wrong pile when stocking.

We won’t notice that plates have been mixed up until a day or two later when reading cultures, and by that point it has already impacted many samples.

Has your lab had this issue in the past, and if so, how did you solve it?
We have tried placing large colorful labels where each plate is to be stacked, but that hasn’t helped.

Looking for any and all advice! Thanks in advance.