Sorry for the inconvenience.
Please check available storage;
Go to "Setting" > "General"" > "About" > check "Available" to see how much free space you have.
If you are still having trouble, please go to the Message tab and click on the Settings icon. Then click on Help center, submit a request with the answers to the following questions and press send.
In which situation is the app slow? While swiping to meet another user? or using other features on the app?