Issue: One database connects and executes with the same credentials when the other one throws an error with the same credentials when executing/selecting a table from the list.
Error: Invalid object name "Table name"
The issue was, The working DB's tables work when
Select * from databasename.dbo.tablename
while the one not working works only when you execute
Select * from databasename.common.tablename
Workaround: Asked customer to use custom query using "common"