There used to be a lot more before covid but that put an end to many of them, there are still some though.
I believe the BBB still hosts a little's event and there is NGM preschool running, there was "something a little different" in Bristol this year but without enough background support they are not running that any more, I've seen a few other munches running around the country.
I'm not sure if ABC club in london is still running or not, and I do believe Little Big Land is still running events.
There may be others but I'd have to go digging around to know for sure, often not a lot advertised this time of year. Forget reddit and google though, go straight to fetlife, most of them are advertised on there in the various groups especially the bgger ones. It's pretty much the only reason I go back to FL now is to find events.