@Nick2339
I am not sure what your minimum stay is, or if you usually get international or more local guests, but when I still did short term, I found January to be the quietest month of the year. So, yes, it could be COVID related seeing as cases here in London are so high and self isolation and testing requirements for arriving in the UK have only been loosened over the past couple of days.
Now that I host only long term guests, all three of my rooms are fully booked for January. I find that January is a popular time for long term guests to start stays, e.g. students returning to university.
I really don't know where you would be able to see what demand is like in London. Under your insights/performance tab, there is a 'conversion rate' section. Here you can compare to 'similar listings' but I really don't know how accurate or useful that is. When you look at the price tips in your calendar, I'm not convinced that the system is comparing our listings to ones that are truly that similar so it's likely that the conversion rate section is pretty useless at this too.
There may also be Apps that could provide you with some info. I used to subscribe to one called your porter/my porter, but that seems to have become Guesty now and isn't free.