diff --git a/web/components/chat/ChatContainer/ChatContainer.module.scss b/web/components/chat/ChatContainer/ChatContainer.module.scss
index 7c224c14b..fc9575ce5 100644
--- a/web/components/chat/ChatContainer/ChatContainer.module.scss
+++ b/web/components/chat/ChatContainer/ChatContainer.module.scss
@@ -16,6 +16,7 @@
   color: var(--text-color-secondary);
   & .toBottomWrap {
     & .toBottomBtn {
+      z-index: 9999;
       border: none;
       background-color: gray;
     }
diff --git a/web/components/chat/ChatContainer/ChatContainer.tsx b/web/components/chat/ChatContainer/ChatContainer.tsx
index e11a17dde..5e05d939e 100644
--- a/web/components/chat/ChatContainer/ChatContainer.tsx
+++ b/web/components/chat/ChatContainer/ChatContainer.tsx
@@ -44,12 +44,12 @@ function shouldCollapseMessages(messages: ChatMessage[], index: number): boolean
     return false;
   }
 
-  if (!lastMessage.timestamp || !message.timestamp) {
+  if (!lastMessage?.timestamp || !message.timestamp) {
     return false;
   }
 
   const maxTimestampDelta = 1000 * 60 * 2; // 2 minutes
-  const lastTimestamp = new Date(lastMessage.timestamp).getTime();
+  const lastTimestamp = new Date(lastMessage?.timestamp).getTime();
   const thisTimestamp = new Date(message.timestamp).getTime();
   if (thisTimestamp - lastTimestamp > maxTimestampDelta) {
     return false;
@@ -185,6 +185,7 @@ export const ChatContainer: FC<ChatContainerProps> = ({
           itemContent={(index, message) => getViewForMessage(index, message)}
           followOutput="auto"
           alignToBottom
+          atBottomThreshold={70}
           atBottomStateChange={bottom => setAtBottom(bottom)}
         />
         {!atBottom && <ScrollToBotBtn chatContainerRef={chatContainerRef} messages={messages} />}