Wagwellies – back ones twist?

Hi – I have a golden retriever whom I recently bought some Wagwellies before. We started with an M size but then exchanged for the L because the M were definitely too tight! However, I've noticed that the back paw shoes tend to twist a little e.g. when she changes positions from standing to sitting. This then makes her back legs walk awkwardly and I will have to fix it every time she sits. Does anyone have any advice?

Also, bonus q: how long did it take for your dog to get used to them and walk "normally"? We've been doing about 5-10mins everyday inside the house for 2 days so far, but she still walks a little clunkily haha.