You are doing nothing illegal, I would continue to work, only when they are out or when it gets dark and they cant see what's going until you get more of an idea what their like, winter is coming and it's getting darker earlier and earlier so plenty of opportunity to work.  Do they go to work at set times? do they have a routine, that would make it easier to plan.

As for the council caring if you work from home, in my case they don't care, very few do, even if you are dobbed in and someone calls them, god knows in my area (home counties) we have had people operating noisy blatant businesses on their front drives, noisy welding, fixing cars, regular massage businesses, Nail techs none of them registered with the council  (I know some of the people who operate them), and even then a blind eye is turned.  They have so much on their plate at the moment, I doubt either the police or the council would bother, unless you had lots of complaints from different people.

Update. Had a visit from community officer today. They were called by neighbour, so had to pop round, but did say they would talk to them as i am doing nothing wrong. Hoping that sorts it.

Good to hear, I hope things calm down for you. Did they ask you questions about your work?

Update. Had a visit from community officer today. They were called by neighbour, so had to pop round, but did say they would talk to them as i am doing nothing wrong. Hoping that sorts it.