Merge pull request #3770 from primefaces/issue-3541

Dropdown: selected disable option issue fixed

components/dropdown/Dropdown.vue

@@ -809,7 +809,7 @@ export default {
             return this.isValidOption(option) && this.isSelected(option);
         },
         isSelected(option) {
-            return ObjectUtils.equals(this.modelValue, this.getOptionValue(option), this.equalityKey);
+            return this.isValidOption(option) && ObjectUtils.equals(this.modelValue, this.getOptionValue(option), this.equalityKey);
         },
         findFirstOptionIndex() {
             return this.visibleOptions.findIndex((option) => this.isValidOption(option));