It is possible this was an intentional change, in which case this is a soft proposal to change it back or at least explore the context. In case it was unintentional, navigating the editor with arrowkeys no longer allows you to select ancestor/container blocks:

Steps to reproduce: have paragraphs before, inside a group, and after, then arrowkey between them. Expectation: the group is selected as part of the flow. That's how it works in latest Gutenberg trunk: