When Derbyshire Community Transport folded, CT4N took over the Travel Derbyshire on Demand service. I know there were a lot of complaints after Hulleys folded where DCC were directing people to use this, but anyone who tried couldn't get a booking for days or even weeks. While the sudden demand spike won't have helped, I wonder how much availability is being affected.
As an aside, I know of at least one person who has cottoned on to the fact that using this service is cheaper than paying for multiple singles or an operator day ticket where two buses are needed to complete a journey. Almost feels like gaming the system, but only works if you know far enough in advance you want to travel to be able to book it.