How to remove/reuse ghost homekit codes ?

I have to cases, one with netatmo Home coach, one with Tado Smart AC Control, where I'cant use my homekit code. The Homekit feedback is "accessory already added" and reset the accessory. But no way with reseting, I get the same Error: it is like a ghost homekit code. How can I reuse my accessory on Home ?

It is not possible to delete the home account because it has more than a hundred accessories!

I have the same problem with a Netatmo Air Quality Monitor. The problem is I can't reset my Netatmo AQ Monitor, because I will loose all my data. I think my homekit code is trapped in my old Homekit account I had deleted 2 years ago because it was instable. Do you have an idea how to ask Apple to liberate old homekit code ? Or do you have experienced such a problem ?

How to remove/reuse ghost homekit codes ?
 
 
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