Funny stuff was happening on my store account after registering.
4 days straight I got 0 sales during the day, but would get a small glut of sales between 7:30 and 9:30. I suspected there might be checkout glitches as they prepared to shift my account over etc, and I know a lot of buyers were experiencing payment issues but only with specific sellers so if nothing else I believe it to be a contributing factor.
However, realistically there could have been other causes - a lot of restrictions have been eased in the last week or so, people going back to work, cafes etc reopening, government support starting to near the end and so on. This all translates to fewer people at home with nothing to do, and maybe not quite the income stability as they go back to work and might not be as confident in job security if their work / business is struggling to get back up and running and all that kind of stuff.
Search is pretty stuffed right now as well - here's a good example if other people get the same results as me.... I just ran a search for stainless steel beads and there is only one result in the first page of 50 that is actually a listing for beads, the rest is chain, wire, keyrings and other assorted findings, some of them don't even have stainless steel in the title, let alone beads. 
Things have definitely picked back up again and I'm now getting orders at all times of the day (though much less during work hours than I was prior to the "deadening", so to speak. 
I'll put this down to most likely being people going back to work, though).
I recall many US sellers saying sales stopped dead after switching to managed payments, as well, but I don't think they meant in the transition phase between registering and actually using managed payments, since for a while buyers couldn't use PayPal with sellers who had switched. However, I have seen this question asked once or twice in seller groups (i.e. anyone else's sales drop off a cliff after registering - it could be coincidental timing with all the social and work restrictions, it could be the managed payments having an effect on various factors such as visibility while eBay updates listings to be able to get switched over - I suspect it's a little from column A and a little from column B).
