By default, the WhatsApp Chat Button shows on bothSometimes, you may have multiple chat buttons or discount buttons on your store. It may even be a simple GDPR bar which is overlapping with your chat button.
You can fix that easily by modifying the height of the chat button. These settings can be found in the Advanced Configuration section of the app.

In most cases of overlapping buttons, a height of 40-100px should solve the problem. Sometimes, it might be better to change the button position to the other side, rather than give it a huge height offset.
Please note that the minimum height offset is 20px, which is the default height. You cannot reduce the height below 20px.