(Question) Are the symptoms of Corona different these days?

My fever persisted, so I went to an ENT clinic and got tested for the flu. The first test was negative. Since it was early, they recommended a retest, so I went again this morning and the final result was negative. It's not the flu, but if an adult has a persistent high fever and it's not the flu, they say it's likely COVID-19. I have a high fever, a runny nose, and a mild cough and phlegm, so I'm a bit confused when they tell me it's COVID-19. What are the main symptoms of the resurgent COVID-19? If you've recently experienced it, please let me know.