@Anneke9
Your profile here is showing you are still a Superhost. Are you sure you lost it this assessment?
Also, Airbnb announced that COVID-19 cancellations/number of stays would not impact this superhost assessment. It will be based on your star ratings and response rate, so how many stays you hosted should not be an issue. If someone at Airbnb told you that, they are wrong, but as the assessment is done automatically by computer, it doesn't sound like human error but some technical glitch. I would contact Airbnb and tell them to reinstate your status.
However, if you don't have the required 4.8 rating or 90% response rate, that might be the real reason.