Kids fake being sick to avoid going to school for a variety of reasons.
Some kids will fake being sick to avoid going to school because they are bullied, hate school, bored of school or they are tired of doing school work.
I used to hate going to school as a kid myself and would fake being sick and it was because I was bored of school, hated school work and would also sometimes be bullied a lot.
I was selective mute as well in school and would whisper to the teacher and I would not talk to anyone else in class or school.
I had and still have selective mutism which made it hard for me to attend school and get along in school.
So ask your kid what is bothering them and why they are avoiding school.
It could be due to the new virus as well or they just hate going to school and ask them if someone is bullying them in school as well.