Record Lookup In Form Flashes One Or More Records Before Displaying The One Selected

I have a form (Student Details) that has an unbound lookup box using a query to select a student. The lookup has the hidden Student ID autonumber key field plus Class Number, Last Name, First Name, Status, sorted by Class Number (descending), Last Name, First Name.

The form record source is a similar but unsorted query.

There are nearly 1000 student records. The form has pages (tabs). The lookup box is in the form header. There are dozens of fields in the 1st Page (General) including an picture (attachment, not hyperlink) field holding a photo of the student, the other 6 pages have less.

When you select a student via the look up, at least one sometimes more students "flash" before it displays the one you want, which seems to display twice before it stops.

I deleted the picture field to see what difference that made, because it seemed to do the most flashing, and indeed, without that field you go right to the record. I looked at the Student table indexes and it seems that field type is not index-able, which is understandable.

Is there any way to improve this with still leaving the photos as attachments? Some thoughts:

It improves if it is displayed first as an Icon or Paper Clip, and probably would if a hyperlink field, but we like to have the picture displayed and not have to open the link to see it nor worry about the location changing invalidating a link. It seems that if the record was displayed with the picture field only filled after all the other fields were filled it would make for a better impression.

Can an On Load form event VBA or Macro be written that either hold the picture back until the rest of the fields are displayed or if an icon or changed to a hyperlink to open. Would it work if the pictures were attached to a separate joined table?