Acknowledging Frank's post in the Transportation Forum - look there for more info.
https://community.ricksteves.com/travel-forum/transportation/aer-lingus-regional-carrier-goes-under
Stobart Airlines, owned by the international trucking firm of the same name, has failed and ceased operations.
They provided 12 routes for Aer Lingus.
They also own(ed) London Southend Airport which had only just reopened since last summer so that passengers could fly from London to Portugal and other Green List countries when 3 weeks later the UK government took Portugal off the Green List and put it on the Amber List (for Covid) causing an immediate drying up of business.
They had been badly hit by the extensive lockdowns and the evaporation of passengers.
An excerpt from an article in the Daily Mirror:
Aer Lingus flyers with cancelled Stobart Air flights can get refunds,
rebook or make insurance claims to get their money back and try to
save their holidays.Stobart Air was a franchise of Irish airline Aer Lingus, and ran
flights on 12 of its routes. But the company stopped trading on
Friday, June 11, cancelling all flights.These flew from Dublin and Belfast City airports to terminals
including East Midlands, Edinburgh, Exeter, Donegal, Glasgow, Leeds
Bradford, Newquay and Manchester.Customers with cancelled flights can get a full refund directly from
Aer Lingus.The airline has asked customers booked on Stobart flights not to come
to the airport, but to check the Aer Lingus website for refund
information at www.aerlingus.com .
https://www.mirror.co.uk/money/stobart-air-collapse-refund-cancellation-24313784