Taste will not come from stock cubes alone. Are you getting the balance of the main ingredients right and it may need some herbs or spices as well and salt/pepper.
Don't rely on stock cubes for the taste ..... add loads of veg etc and seasoning. Taste as you go...I generally make a really thick soup and water it down if it won't pour! Just finishing off the xmas veg in soup form...I don't ever waste left overs so often make soup...all I can taste arevegetables...we had a lot of leftovers!!
Are your taste buds working well ?
Did you remember to add sufficient salt ?
Are your ingredients top quality of produced as cheaply as possible ?
Are your herbs & spices past their 'use by' date ?
I used to find that but when I make chicken soup I use chicken thighs or drumsticks (with bones) BUT I do cook them in muslin bags because they break up so finely but the taste is superb.