Sudden decrease in bloodsugar after meal

My father was ill from 5 August and had loose motions for 2 days and continuous mild fever. On  20 August we got him tested for COVID 19 and on 21 August his result came positive. Same day he got admitted to private hospital and same day he was diagnosed with type 2 Diabetes and his bloodsugar levelwas 249(R)  .After discharging he was asked to take glycomet GP-1 tablet only one before breakfast . I bought Dr Morepene glucometre bp03 to check his status . On 25 August he got discharged and asked to home quarantine and given antibiotics for 15 days . On 30 Aug he took blood sugar level test and it showed 135 empty stomach and 184 after two hours of food . He maintained healthy lifestyle good diet and exercise and his blood glucose level started coming normal no symptoms. On13 Sep empty stomach sugar level was 135 and after 2 hrs of lunch150. On 20 Sep empty stomach sugar level was 116 and after 2 hrs of lunch 110. Why after lunch it was less? Is this progress normal? Anything to worry?