I think a bit of a recap is required at this point :
7 Feb - Traffic warden issues fine
20 Feb - Informal challenge submitted
4 March - Informal challenge rejected
I keep waiting for letters in post and nothing arrive.
Then, I check my V5 and see that my address is that of my other property from which I moved to my current property this year but thought I had updated it!
Unknown date - NTO sent to other address, this has been binned by tenant
6 May - Charge certificate sent to other address, this was retained by tenant
12 May - Updated address with DVLA. New V5 rcvd shortly after
22 May - Informed LA to update address
12 June - General letter / payment reminder from LA to correct address
30 July - PCN is registered with TEC
18 Aug - I phone TEC and they inform me when PCN was registered with them and email me TE9 form
"notified the council of your change of address for correspondence"

"they sent documents relating to the PCN to your new address"

I will ask my tenants at my old address if the OfR has turned up.