Fix: InfiniteScroll sometimes can not fetch next page (#7550)

### What problem does this PR solve?

https://github.com/infiniflow/ragflow/issues/7538

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

web/src/pages/flow/list/index.tsx

@@ -70,15 +70,29 @@ const FlowList = () => {
       </Flex>
 
       <Spin spinning={loading}>
+        <div
+          id="scrollableDiv"
+          style={{
+            height: 'calc(100vh - 200px)',
+            overflow: 'auto',
+          }}
+        >
           <InfiniteScroll
             dataLength={nextList?.length ?? 0}
             next={fetchNextPage}
             hasMore={hasNextPage}
             loader={<Skeleton avatar paragraph={{ rows: 1 }} active />}
-          endMessage={!!total && <Divider plain>{t('noMoreData')} 🤐</Divider>}
+            endMessage={
+              !!total && <Divider plain>{t('noMoreData')} 🤐</Divider>
+            }
             scrollableTarget="scrollableDiv"
+            scrollThreshold="200px"
+          >
+            <Flex
+              gap={'large'}
+              wrap="wrap"
+              className={styles.flowCardContainer}
             >
-          <Flex gap={'large'} wrap="wrap" className={styles.flowCardContainer}>
               {nextList.length > 0 ? (
                 nextList.map((item) => {
                   return <FlowCard item={item} key={item.id}></FlowCard>;
@@ -88,6 +102,7 @@ const FlowList = () => {
               )}
             </Flex>
           </InfiniteScroll>
+        </div>
       </Spin>
       {flowSettingVisible && (
         <AgentTemplateModal