In HRD, if I use an ampersand (&) in the Comments field, and upload the log entry to QRZ, QRZ rejects the upload: "missing <EOR> in record".
Special charters are best left out of a somewhat plain text file. Many times you can put a entry in quotes " This is a test & it worked" To avoid a EOF or EOR errors. The "&" screws with the End Of Record in your case. A Under Score _ works for me to add comments, Even in a file name. Good Luck. The structure if a ADIF file seems to be well documented. Maybe a update is in order ??? But it does work As Is for most users.