diff --git a/packages/runtime-core/src/componentRenderUtils.ts b/packages/runtime-core/src/componentRenderUtils.ts
index 6b3be672792..8738da5660f 100644
--- a/packages/runtime-core/src/componentRenderUtils.ts
+++ b/packages/runtime-core/src/componentRenderUtils.ts
@@ -64,6 +64,13 @@ export function renderComponentRoot(
       result = normalizeVNode(
         instance.render!.call(proxyToUse, proxyToUse, renderCache)
       )
+      // root node should inherit class/style in component tag and patch
+      if (vnode.patchFlag & PatchFlags.CLASS) {
+        result.patchFlag |= PatchFlags.CLASS
+      }
+      if (vnode.patchFlag & PatchFlags.STYLE) {
+        result.patchFlag |= PatchFlags.STYLE
+      }
     } else {
       // functional
       const render = Component as FunctionalComponent
@@ -183,7 +190,7 @@ export function shouldUpdateComponent(
       return hasPropsChanged(prevProps!, nextProps!)
     } else {
       if (patchFlag & PatchFlags.CLASS) {
-        return prevProps!.class === nextProps!.class
+        return prevProps!.class !== nextProps!.class
       }
       if (patchFlag & PatchFlags.STYLE) {
         return hasPropsChanged(prevProps!.style, nextProps!.style)