Gstr-1 and gstr-3b for f.y. not loading. and the customers details changes automatically.

Hi @info1149  , for gstr-1 and gstr-3b error, there are several problems and steps to fix it, you could read   This article 

For making right customer details, you can edit to the right customer details with this following steps.

iOS

1. From the Menu ☰, select Customers.
2. Select the customer name you want to edit.
3. Select Details, then select Edit ✎.
4. Make your changes, then select Save.

Android

1. From the Menu ☰, select Customers.
2. Select the customer name you want to edit.
3. Select Details, then select Edit ✎.
4. Make your changes, then select Done.

Edit customer details 

Related article : Set up customer in QBO 

Comment back if it still change automatically or having other questions.