Stp – it’s a mystery why some applications are processed quickly and others take such a long tim
This may help explain it – there are two routes through the application process – digital and manual -if all the checks etc can be completed on the digital route the application is processed faster, you don’t have a processing stage you go from docs received to approved in one step.
If however the digital checks can’t be completed or some other issue arises you drop out of the digital route into the manual route – you then get the processing stage update. Requesting a call back can be enough to drop your application out of the digital route.
Of course everyone’s application is individual to them so other factors may come into play.
I was lucky I applied on the 21st Feb and had the passport in my hand on 22nd March – with no processing update. I gathered this information from staff guides which are available online if you google them.