Weird behaviour by the recruiter

I have been interviewing with this company, and I have completed two rounds. I believe the last round went well. However, after that, I received no response. I tried calling the HR two days later, but they did not answer but on the same day, at night, I received an email from HR stating that they would like to continue the process and schedule the upcoming rounds. They asked me to schedule the interviews using a link provided. I received this email on Friday night. Now it's Monday morning and they still haven't scheduled my interviews.