I found an instance of a client that turned Active twice in a row, with no status change in between. When I further investigated this client, I discovered over a dozen reasons why the client should be currently active. I tried manually triggering the client to become active, and nothing happened. Client seems stuck on inactive status.

I tried making some other clients active in 61.1 and it didn't work for any of them. Then I tried in the demo site, and it WAS working. The demo site is on 61.1.1. I installed 61.1.1 on my site and now OTHER clients are activating correctly, but this SINGLE client is still stuck. So I think the issue is widespread in 61.1, but fixed in 61.1.1, except for whatever weird edge case I found.
Here's the full story for this single client.
Now all of those transactions predate me updating to 61.1 so I thought I'd figure out what happened when I tried to do something afterwards. So I tried booking into shelter, but noticed the consent was expired. So I added a new consent - no status change. And then I booked him into shelter - still no status change. Client is very happily inactive despite lots of activity over the past several years.