diff --git a/internal/handlers/koreader.go b/internal/handlers/koreader.go
index e7b3461..895ebea 100644
--- a/internal/handlers/koreader.go
+++ b/internal/handlers/koreader.go
@@ -622,11 +622,19 @@ func (h *KOReaderHandler) GetMetadata(c *echo.Context) error {
 		Percentage: progress.Percentage.Float64,
 	}
 
-	if progress.Epubcfi.Valid {
-		progressData.Epubcfi = &progress.Epubcfi.String
-	}
-	if progress.Epubcfi.Valid && wsync.IsStandardEPUBCFI(progress.Epubcfi.String) {
-		h.convertCFIToXPointer(c, mediaItem, progress, &progressData)
+	// CFI/xpointer are meaningless for image-based fixed-layout content; the
+	// page index is the canonical locator. Only return them for reflowable docs.
+	formatGroup := wsync.FormatGroup(mediaItem.FormatGroup)
+	isFixed := formatGroup == wsync.FormatGroupFixedLayout ||
+		formatGroup == wsync.FormatGroupComicArchive
+
+	if !isFixed {
+		if progress.Epubcfi.Valid {
+			progressData.Epubcfi = &progress.Epubcfi.String
+		}
+		if progress.Epubcfi.Valid && wsync.IsStandardEPUBCFI(progress.Epubcfi.String) {
+			h.convertCFIToXPointer(c, mediaItem, progress, &progressData)
+		}
 	}
 	if progress.Chapter.Valid {
 		progress := int(progress.Chapter.Int32)
diff --git a/internal/sync/progress.go b/internal/sync/progress.go
index 6ee754f..ec3c647 100644
--- a/internal/sync/progress.go
+++ b/internal/sync/progress.go
@@ -404,8 +404,11 @@ func (s *ProgressService) SaveProgress(ctx context.Context, req SaveProgressRequ
 	isFixed := formatGroup == FormatGroupFixedLayout || formatGroup == FormatGroupComicArchive
 	if isFixed {
 		// Fixed-layout & comic formats: the page index is the canonical locator.
-		// Derive percentage from page; CFI/character-offset are meaningless for
-		// image-based content, so they are intentionally left untouched here.
+		// CFI/character-offset are meaningless for image-based content, so clear
+		// any stale value that may have been stored by the web reader (which
+		// generates fake CFIs for comics).
+		params.Epubcfi = pgtype.Text{}
+		params.CharacterOffset = pgtype.Int8{}
 		if params.CurrentPage.Valid && params.TotalPages.Valid && params.TotalPages.Int32 > 0 {
 			pct := PageToPercentage(int(params.CurrentPage.Int32), int(params.TotalPages.Int32))
 			params.Percentage = pgtype.Float8{Float64: pct, Valid: true}