https://ukaviation.news/ryanair-turns-back-on-southend/
Interesting sentence
Eskin Group, which owns the airport, said that Ryanair was closing its base as a result of the coronavirus pandemic but despite losing over 50 flights as a result, the financial impact would be negligible due to the large cost of servicing the Ryanair base.
Sounds like SEN was making no or little money out of Ryanair. Did Ryanair demand a further discount that was turned down?