So word's out that Unbound are in financial trouble. Report linked below includes official info, but I can add that it's been going on over a year. I've had two payments for Shareware Heroes delayed (but later paid) due to cashflow problems and now a third is overdue.

Causes that I know of are expected funding/investment evaporating last-minute, expansion plans not going as well as hoped, and shipping costs blowouts from war and COVID (which stung them because they charged shipping upfront for upcoming crowdfunded books, then costs doubled).
https://www.thebookseller.com/news/exclusive-unbound-faces-financial-uncertainty-as-authors-wait-for-delayed-payments