Decode appearance keys of checkboxes

src/core/annotation.js

@@ -3290,7 +3290,7 @@ class ButtonWidgetAnnotation extends WidgetAnnotation {
         ? this.data.fieldValue
         : "Yes";
 
-    const exportValues = normalAppearance.getKeys();
+    const exportValues = this._decodeFormValue(normalAppearance.getKeys());
     if (exportValues.length === 0) {
       exportValues.push("Off", yes);
     } else if (exportValues.length === 1) {

test/pdfs/issue19753.pdf.link

@@ -0,0 +1 @@
+https://github.com/user-attachments/files/19566810/PDFjs_fails_checkboxState.pdf

test/test_manifest.json

@@ -12114,5 +12114,14 @@
     "md5": "2abe67c8b34522feb6b85d252dde9d3e",
     "rounds": 1,
     "type": "eq"
+  },
+  {
+    "id": "issue19753",
+    "file": "pdfs/issue19753.pdf",
+    "md5": "6b1fe0af506860002a9411f5f0d6437f",
+    "rounds": 1,
+    "type": "eq",
+    "forms": true,
+    "link": true
   }
 ]