TRANZACT Data Scientist interview questions

I am not sure how the process works because they kept scheduling and canceling interviews. A couple weeks after I applied online, a recruiter contacted me for a HR screening interview. I let her know the time but she canceled it less than an hour before the scheduled time. I even left my work early for that. She asked me about other times and I let her know. A week later on the day, I had this feeling that she might cancel it again so I emailed her to confirm the interview 20 minutes before the scheduled time. Of course, she said she wouldn't be able to do it with an excuse that she had some COVID situation. To this day, I don't know what kind of a COVID situation could prevent someone from interviewing candidates over phone. Although she asked for another time and I let her know again, she didn't reply.