According to our experience, the App works slower when the phone becomes too full or too old. In other words the performance of the App is not dependent on the App itself, but rather on the ability that your phone has to process data.
Try to keep your phone with the latest update all the time, and consider that most phones will naturally become slower when their memory is very full or after a few years of use.
You can also try to delete the app and then re-install it on your phone.
If the problem is of a different nature, you’re welcome to contact our support and explain the issue.