Macmillan Learning interview questions

Initial interview with HR. Pretty standard phone screening call. Second round - Met with the team lead. Great conversation and another pretty standard interview. Third Round - I was given a case study to interpret and answer. I spent a lot of time working on this and was told it needed to be completed over a holiday weekend (pretty unprofessional in my opinion). After that, I was ghosted and never received any feedback. Eventually I got a generic rejection email. The salary for this job is very low for industry standards anyway. I was told there would be a 4th round in which credentials to the platform would be given and you would have to do a mock onboarding call for a panel.