Mail preview is displaying mail header, etc

i have IPad Air 3rd gen, - since the most recent update (13.1.3), my mail preview screen is not consistently displaying headers and 2 lines of the mail. Instead, there are empty areas in the listing, and when I select the empty area, the mail content becomes visible, and most times, the mail header and 2 lines then become visible in the preview, but not always. I sometimes have to rpeatmepselecting and closing several times before it becomes visible permanently in the preview.

i have closed mail, powered off my device completely, and in settings, have re-selected my prior settings for preview and mail, and the problem appears corrected, but then issue starts again.