Abbylynn was like this when I first brought her home at 5 months old. I just started potty training all over again as if she was a new puppy. ( as you have already appear to have started doing with your pup) Abbylynn has never pooped in the house in the 7 months she has been with me. But after pretending she was a 10 week old ... it worked. Always take your girl out right after she eats since she seems to go immediately. I would also take her out even more often than you already are for a while longer. She probably is confused and was never really potty trained to begin with. Sometimes they say they are to help get them adopted out. 
The minute she makes a mistake, just ignore it and immediately take her outside anyways. Don't scold her or she will be afraid to go potty anywhere in front of you, even outside. Scolding makes matters even worse. Clean up soiled areas with an enzymatic cleaner or vinegar and water, a 50/50 solution to rid the urine smell or she will keep going in the same area over and over again. You may already know most of this ..... just trying to help.
Good luck. It took Abbylynn and I a few months ... but we are good to go now! I personally do not think your dog was ever really potty trained. It may take a while for it to sink in. Every dog is different.
The minute she makes a mistake, just ignore it and immediately take her outside anyways. Don't scold her or she will be afraid to go potty anywhere in front of you, even outside. Scolding makes matters even worse. Clean up soiled areas with an enzymatic cleaner or vinegar and water, a 50/50 solution to rid the urine smell or she will keep going in the same area over and over again. You may already know most of this ..... just trying to help. Good luck. It took Abbylynn and I a few months ... but we are good to go now!
I personally do not think your dog was ever really potty trained. It may take a while for it to sink in. Every dog is different.
