More anecdata - I suspect this has been around for longer than official timelines suggest. I had symptoms that left me unable to get out of bed for a few days in February. At the time 111 was only interested if you'd been to Italy/China. Who knows though, could have been flu.
@JamesQGM I've been meaning to reply to you for ages, but I've generally been too knackered. Both my partner and I took about 8-10 weeks to get over the absolute exhaustion from doing the simplest things. At about 3 weeks after the main symptoms I was getting muscle aches from a gentle 5km run, and feeling shattered for a day or so after. We changed everything we did to prioritise resting over everything else (can be hard as we have a toddler). After 3 months I think I'm back to normal.