Custom connector behaviour - resetting credentials

I have noticed that when you use connectors method multiple times in different data sources, but with the same arguments it will not ask you for credentials too often, but when you have multiple sources setup with different arguments it will reset all of them and require typing every time: when you change more than 1 data source arguments at a time before refresh. 

Is there a way around it ? 

It makes it unusable with that feature/bug of resetting credentials. e.g when I change time selection globally across all my methods I cannot type 10 passwords and usernames everytime.