GA highlights intermittently missing

# GA highlights intermittently missing

The inline highlights produced by the Grading Assistant sometimes don't render on the graded paper. Comments may still appear, but the on-doc highlights are gone.

## Reproduction

Not reliably reproducible. Reported as an intermittent symptom: "I'm not getting the GA highlights all of a sudden."

## Expected

Every GA run that produces comments also produces inline highlights anchored to the relevant text spans.

## Actual

Some runs produce comments without highlights. Whether highlights render appears non-deterministic.

## Impact

Loss of the most actionable part of the GA output — students rely on highlights to see exactly which span a comment refers to. Reported 2026-04-13. Likely related to or partially overlapping with [ga-flaky-grading-and-incomplete-markup](ga-flaky-grading-and-incomplete-markup.md).

## Affected versions

Reported 2026-04-13.

## Suspected cause

Anchor resolution failing — the GA returns highlight spans by character offset or text snippet, and the anchors don't match the rendered document (off-by-one, whitespace mismatch, paragraph join issue). Could also be a render-time race where highlights load before the document body.

## Workaround

Re-run GA. Sometimes the second run renders correctly.