Version 0.5.5 brought a layout bug to Events, Payments: the “Endpoint details”, “Use a restricted API key instead” and “Set up the webhook” sections were squeezed into a narrow column, so their text ran down the page one word at a time. 0.5.6 puts them back to full width.
Only the look of that screen was affected. Stripe connections, webhooks, bookings and payments all kept working as before.
The cause was a style added for the chart legend on the new Reports screen, which happened to share a name with those sections. Sorry about that.
Update from your WordPress dashboard, or see the changelog.