
Here is the trick:
- Tap and hold the older message that you want to be the topic
- Then Click the Reply icon (Android) or Reply text (iOS)
|  | 
| 'Reply' icon on Android | 
|  | 
| 'Reply' on Ios | 
Tips trick about Computer & Smartphone.

|  | 
| 'Reply' icon on Android | 
|  | 
| 'Reply' on Ios |