I feel your pain. Here in south London we are infested with foxes. I have 2 issues: they defecate on my plot and it stinks. They also trample plants and crash into nets, smashing the plants under them when they are young, I’m afraid they evoke very un PC feelings in me. Nothing is 100% effective but a couple of things may help. I put sharp things under the nets eg broken sticks so when they jump on them they get a shock. I erect obstacles on the plot so they can’t have a clear run though, for example sticks, bricks, metal mesh etc.
Finally, they are thought to hate the smell of disinfectant so I brush Jeyes fluid on bricks and place them around the plot. Good luck!