I play on bluestacks 5 and can usually access my main account by closing bluestacks and reopening it. This is because bluestacks always reverts to the account saved to the device and not saved to another account (google, EA, or otherwise) (my main account is linked to my google account)
I went through the process to login to my old google account lately because I got a new computer. If you can't find the login for a google account, you may have to level a bit on this account. It took me till level 12 on my newer account for it to give me the option to login to my old one. I am not sure if that has to do with swgoh or not
Hope this helps.
This was summarized by darkstar007
Edit:
Additionally, make sure bluestacks is fully closed if it is running in the background restarting bluestacks will do nothing.
To do this hit Ctrl (cmd on mac (don't know if this works on mac but I figure it would be easier as swgoh is supported by apple and not windows/samsung)) + Alt + Delete and hit Task Manager. Then hit bluestacks and end task.