diff --git a/.changeset/amber-cobalt-spark.md b/.changeset/amber-cobalt-spark.md
new file mode 100644
index 000000000..f422f0b35
--- /dev/null
+++ b/.changeset/amber-cobalt-spark.md
@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 3377
+---
+**`requirements mark-complete` now flips the traceability row when `## Traceability` holds more than one table** — `updateTableCell` no longer binds to the first table in the section; it scans for the table that actually carries the requested column. A section with a phase-summary table above the requirement rows previously made the Status write silently bail (`table_unmatched`) while the checkbox still flipped, leaving the row at `Pending` indefinitely. Single-table sections are unchanged. (#3255)
diff --git a/src/markdown-table.cts b/src/markdown-table.cts
index 0c76ce5b3..ee0c447a4 100644
--- a/src/markdown-table.cts
+++ b/src/markdown-table.cts
@@ -326,36 +326,50 @@ export function updateTableCell(
 ): Result<string> {
   const lines = splitLinesWithOffsets(tableText);
 
+  // #3255: pick the first VALID table whose columns include `column`. The prior
+  // code bound to the FIRST table of any shape and returned 'unknown column' if
+  // that one lacked the column — so a section holding a summary table above the
+  // target (e.g. ## Traceability: a phase-summary table, then the requirement
+  // rows) never reached the target table. Scan for the first valid table that
+  // carries the column; if none does but a valid table exists, still return
+  // 'unknown column' (single-table behaviour unchanged). Track the first
+  // malformation reason so a lone malformed table keeps its specific error.
   let headerIdx = -1;
+  let columns: string[] = [];
+  let firstValidIdx = -1;
+  let firstMalformedReason: string | null = null;
+  const recordMalformed = (reason: string): void => {
+    if (firstMalformedReason === null && firstValidIdx === -1) firstMalformedReason = reason;
+  };
   for (let i = 0; i < lines.length; i++) {
     const trimmed = lines[i].line.trim();
-    if (trimmed.startsWith('|') && trimmed.indexOf('|', 1) !== -1) {
+    if (!trimmed.startsWith('|') || trimmed.indexOf('|', 1) === -1) continue;
+    const delimiterLine = lines[i + 1]?.line;
+    if (delimiterLine === undefined || !delimiterLine.trim().startsWith('|')) {
+      recordMalformed('missing delimiter row');
+      continue;
+    }
+    const candidateRanges = splitTableRowRanges(lines[i].line, lines[i].start);
+    const candidateColumns = candidateRanges.map((r) => unescapeCellText(tableText.slice(r.start, r.end)));
+    const delimiterCells = splitTableRow(delimiterLine);
+    if (!isDelimiterRow(delimiterCells)) {
+      recordMalformed('missing delimiter row');
+      continue;
+    }
+    if (delimiterCells.length !== candidateColumns.length) {
+      recordMalformed('delimiter/header column count mismatch');
+      continue;
+    }
+    if (firstValidIdx === -1) firstValidIdx = i;
+    if (candidateColumns.includes(column)) {
       headerIdx = i;
+      columns = candidateColumns;
       break;
     }
   }
   if (headerIdx === -1) {
-    return { ok: false, reason: 'no table found' };
-  }
-
-  const delimiterLine = lines[headerIdx + 1]?.line;
-  if (delimiterLine === undefined || !delimiterLine.trim().startsWith('|')) {
-    return { ok: false, reason: 'missing delimiter row' };
-  }
-
-  const headerRanges = splitTableRowRanges(lines[headerIdx].line, lines[headerIdx].start);
-  const columns = headerRanges.map((r) => unescapeCellText(tableText.slice(r.start, r.end)));
-
-  const delimiterCells = splitTableRow(delimiterLine);
-  if (!isDelimiterRow(delimiterCells)) {
-    return { ok: false, reason: 'missing delimiter row' };
-  }
-  if (delimiterCells.length !== columns.length) {
-    return { ok: false, reason: 'delimiter/header column count mismatch' };
-  }
-
-  if (!columns.includes(column)) {
-    return { ok: false, reason: `unknown column: ${column}` };
+    if (firstValidIdx !== -1) return { ok: false, reason: `unknown column: ${column}` };
+    return { ok: false, reason: firstMalformedReason ?? 'no table found' };
   }
   const targetColIdx = columns.indexOf(column);
 
diff --git a/tests/markdown-table.test.cjs b/tests/markdown-table.test.cjs
index f3d5ed37f..e7f7d179e 100644
--- a/tests/markdown-table.test.cjs
+++ b/tests/markdown-table.test.cjs
@@ -639,6 +639,29 @@ describe('updateTableCell', () => {
     assert.match(result.reason, /no table found/);
   });
 
+  test('#3255: reaches a later table when the first table lacks the requested column', () => {
+    // A ## Traceability section holding a phase-summary table (no Status) ABOVE
+    // the requirement table (with Status). The prior code bound to the FIRST
+    // table and returned 'unknown column: Status' without ever reaching the
+    // requirement table, so requirements.mark-complete left the row at Pending.
+    const multiTable = [
+      '| Phase | Name | Requirements |',
+      '|-------|------|--------------|',
+      '| 1 | Portal Spec | 4 (PORTAL-01..04) |',
+      '',
+      '| Requirement | Phase | Status |',
+      '|-------------|-------|--------|',
+      '| AUTHZ-02 | Phase 02.2 | Pending |',
+    ].join('\n');
+    const byReq = (row) => (Object.values(row)[0] ?? '').trim().toLowerCase() === 'authz-02';
+    const result = updateTableCell(multiTable, byReq, 'Status', ' Complete ');
+
+    assert.equal(result.ok, true, `expected ok:true (should reach the requirement table); got: ${result && result.reason}`);
+    assert.ok(result.value.includes('| Phase | Name | Requirements |'), 'first (summary) table header untouched');
+    assert.ok(result.value.includes('| 1 | Portal Spec | 4 (PORTAL-01..04) |'), 'first (summary) data row untouched');
+    assert.ok(/AUTHZ-02 \| Phase 02\.2 \| Complete/.test(result.value), 'second table Status cell flipped Pending → Complete');
+  });
+
   test('5-column milestone table: Milestone cell and other columns stay byte-identical', () => {
     const byPhase = (row) => row['Phase'].trim() === '1. Alpha';
     const result = updateTableCell(fiveCol, byPhase, 'Plans Complete', ' 2/2 ');