Experimenting with a private -regtest network, I found the following behaviour that seems wrong: I've got two nodes, A and B. They are initially disconnected and A has a chain of height 210 while B has one of height 220 - they are forked at block 200. Now I want to connect the nodes and expect that A switches to B's longer chain.

When I connect A to B (addnode call on A), this is precisely what happens. However, when I connect B to A (addnode called on B), both keep their chains. This seems very odd to me. I seem to recall that "a few days ago" both alternatives resulted in the nodes syncing to the same chain. (And can try to find out more about this / give more details if necessary.)