I have a Bissell Pro Heat Carpet Cleaning Machine?

and I always used Bissell Carpet Cleaning Shampoo....but I went to Lowe's to get some and had to get the off brand b/c they didn't have any. Well there were bubbles everywhere in the machin and on the floor....I tried going back over the carpet with plain water but still their were suds everywhere....what happened? I used the recommended amount?