Hi Robi
I was in a similar position as you, just got mine approved (I submitted my application 24/3/22)
There’s no clear guideline as to when this ‘10week’ clock start – possibly intentional so no one can really complain of delays.
I ended up asking my MP for support as I was getting absolutely no where with the passport office. Whether that has anything to do with my application going through after nearly 3 months since applying we will never know but worth trying!
Good luck – I will now wait for mine to be printed and delivered- probably another few weeks wait.