little correction

src/Umbraco.Web.UI.Client/src/packages/core/data-type/components/data-type-flow-input/data-type-flow-input.element.ts

@@ -28,7 +28,7 @@ export class UmbInputDataTypeElement extends FormControlMixin(UmbLitElement) {
 	 * @param {string} dataTypeId
 	 * @default []
 	 */
-	@property({ attribute: false })
+	@property({ type: String, attribute: false })
 	get value(): string {
 		return super.value?.toString() ?? '';
 	}

src/Umbraco.Web.UI.Client/src/packages/core/modal/common/property-settings/property-settings-modal.element.ts

@@ -237,7 +237,7 @@ export class UmbPropertySettingsModalElement extends UmbModalBaseElement<
 										.value=${this._returnData.description}></uui-textarea>
 								</div>
 								<umb-data-type-flow-input
-									.value=${this._returnData.dataTypeId}
+									.value=${this._returnData.dataTypeId ?? ''}
 									@change=${this.#onDataTypeIdChange}></umb-data-type-flow-input>
 								<hr />
 								<div class="container">