I haven't yet installed 25.03, but can confirm problem with Ctrl+C on old version (OS is Win 7). Assuming behavior is the same, Ctrl+C is guaranteed to fail if your mouse cursor is over one of the tabs (and when you want to copy from one tab to another, it often is). It probably redirects all keyboard events to tab manager so that you can navigate with arrows, but it works horribly. Apart from Ctrl+C it is also annoying that it will not type any text if your cursor accidentally hovers over some tabs. And it doesn't even provide any convenience, since to navigate with arrows you still need to first hover your mouse over tabs but then you can just click tab with mouse.
I'm not sure, how it happens. My experience: longer I use CB after starting it - lesser chance of successful Ctrl+C. In most cases it works just after starting. But then it becomes worse and worse. For example just few hours ago I experimented with it a little bit. First I was able to copy things on the second attempt. But then it stopped working completely.
I thought, that being unable to type anything was somehow connected to auto-completion getting stuck sometimes. It feels like 25.03 is less prone to this problem.