Don’t panic if you notice your I-94 looks different than it has in the past. CBP announced that, due to the depletion of 11-digit I-94 numbers, it will begin issuing I-94s with both letters and numbers starting in May 2019. According to CBP, the 10th position will be replaced with a letter.
As a reminder, every foreign national should check his or her I-94 record upon each arrival into the United States. To look up your I-94 record, go to https://i94.cbp.dhs.gov/I94/#/home. Print the I-94 for you (and family members) and provide a copy (or copies) to your attorney.