* lisp/frame.el (frame-monitor-attributes): Fall back to the last monitor

when frames monitor attributes is still uninitialized.  (Bug#34680)

lisp/frame.el

@@ -1696,7 +1696,10 @@ keys and their meanings."
   (or frame (setq frame (selected-frame)))
   (cl-loop for attributes in (display-monitor-attributes-list frame)
 	   for frames = (cdr (assq 'frames attributes))
-	   if (memq frame frames) return attributes))
+	   if (memq frame frames) return attributes
+	   ;; On broken frames monitor attributes,
+	   ;; fall back to the last monitor.
+	   finally return attributes))
 
 (defun frame-monitor-attribute (attribute &optional frame x y)
   "Return the value of ATTRIBUTE on FRAME's monitor.