@htdvisser, thanks for the info about the current owner - without this I deducted from the json the gw doesn’t have an owner. I’ve just sent him/her a priv message to sort out the problem *wanted t add you in cc, but you’re not accepting messages 
)
In fact I bought 2 new TTIG in May 2020 from maker-shop - which was the only place to buy it in Switzerland. I registered the first TTIG without a problem just after the purchase. The second one was not so lucky.
Hopefully @Farm21 will clear out if there are two TTIG with the same id of there was a fixable mistake.