Same cell lines show different phenotypes in different laboratories

The HEK293T cell in my current laboratory strongly adheres to the bottom of culture dishes. In contrast, the cell in my previous laboratory didn't show this property, which means that it had the tendency to be dissociated from the bottom of culture dishes easily. So I used to use a Gel Matrix that consists of collagen, which makes cells adhere to the bottom of  dishes strongly, in the previous laboratory. Because I had expected that the HEK293 T cell in my current laboratory also didn't adhere to the bottom of culture dishes, I had bought a biological item that is similar to Gel Matrix before starting the cell culture. However, I have never used the product since I had come to my current laboratory because my HEK293 doesn't need the acceleration of adhering activity.