My delivery process was:
Passport delivered by TNT – 21 March 2022
Supporting documents returned by Royal Mail – 16 March
Passport printed – 14 March 2022
Application approved – 11 March 2022
Like some others on this forum, I never received any updates from TNT. I kept checking their tracker using my postcode and Passport Office reference number regularly and my passport started showing up on the TNT system from 18 March.