There are generally two reasons for bar overlapping on your shopify store. Please check solution below for both issues.
A. Shopify Admin Bar Overlap
1. When you login into the Shopify admin and at the same time you login into your store. You probably see this bar cover up your website header, that is not an error. It shows because you have login Shopify store from the same browser that you log into your store, kindly check your website in another browser or device.
2. If you have enabled different bars at the same time, then It might be possible to overlaps the bar.
To resolve this error from your store, please uncheck the sticky option from the app.
B. Your store Sticky Menu Bar Overlap
1. Go to the bar and uncheck the sticky box from the option available in the app and save settings.
If It still shows you on store, kindly write to our support team and our team will resolve your issue quickly.