issues with potty training puppy from the shelter

i adopted our puppy about a month ago and the shelter estimated her to be about 3-4 months old at the time of adoption, give or take.

at this point, she knows to do her business outside and immediately does when we go out. however, even if she does #1 and #2, she will do both again inside within 20 minutes with no warning, and we are taking her out every hour or if she goes to the door. she will also go in her crate even though it is a small one.

our other dog was not from the shelter and had a much more solid and consistent potty training routine from a much younger age, so we are unsure of where to go from here. especially because this isn’t our new puppy’s fault, obviously— she was caught as a stray and spent a month going in a kennel and was going in there instead of going outside. any tips? we used bells on the door with our other dog and tried that again with our new puppy to no avail.