Importing receivable trans and ref numbers

I imported receivables into BV from another BV account that I exported from. I added a letter in front of the reference number ex P and now in a lot of cases it doesn't show the last digit on the reference number ex P1000005861 shows up as P100000586 - I have info in that field that is longer than the 10 characters so assume it wasnt a maximum field length of the ref field issue