This is not a technical issue (as in the meaning of software/development)
It is a legal and fiscal issue. Your ISA held instruments which it cannot hold, so it is “broken”
There are two options your ISA will be completely voided or repaired.
If it is your(customer) fault than the ISA will be voided or “if it is the ISA managers fault (T212 in this case)” there is a chance ISA manager can repair the ISA. And trust me repairing is neither an easy nor pleasant process.
In the lamest terms repairing involves (lets take NIO for example) pretending like you never bought NIO in the first place. but the monetary value of your monies intrinsically gained or lost.
So there is not a chance to “transfer” a share from place A to B, you never held or bought that share, because if you did buy that share in your ISA, your account is voided.
This is not the first time this happened, get used to it. Mistakes happen I’ve recently post this same thing happening on Interactive Investor for SEA Ltd.
edit: original post. Notice they did not even notice the problem. I did and warned them: