Well it could be. The printer needs more calibration.
It’s colder now, so maybe the temperature is affecting things. I’ve added some cardboard to try and keep the heat in, and stop any cool drafts from interfering.
This website is a collection of all of the things I've been doing with my 3D Printer.
You'll find lots of examples of badly modelled things, poorly printed things, and a lot of wasted plastic!