I had an issue similar to Trying to save/download configuration gives an error - TrueNAS General - TrueNAS Community Forums
My NAS was a fresh 25.10.1 install and today I received the notice that update 25.10.2 was available.
I tried many to configuration both from the install window and from the System → Advanced settings → Manage configuration → Download file but I kept on having the spinning arrow like this:
Reading the thread above, I configured Connect (it wasn’t before) and finally I could manage to download it.
How can I help you to help me to solve this issue?