Strep A not resolving

So… I’ve had this white coating on the back of my tongue since October 2025. GP thought it was oral thrush ?induced by stress. Was prescribed Nystatin, Fluconazole and Miconazole gel over a number of weeks to try and treat. Nothing resolved it. Eventually swabbed which came back as strep A. No sore throat, no fever, no other symptoms. This white coating began around 2 weeks after having Covid. Unsure if there’s any link there due to one being viral and the other bacterial. I’ve had 7 days of Amoxicillin and now started on Erythromycin as the swab report showed the strain was sensitive to these. So far on Erythromycin not seeing any signs of it going away. Has anyone else experienced this? GP says next course of action is referral to oral medicine if Erythromycin doesn’t resolve it. Male, 34 years old, 6ft2 height, 14st 4lbs weight. Takes sertraline for anxiety. No other health conditions. Generally fit and well.