Mr Diego there is an issue with the signer. I don't know if you are aware of it.
Thank you for the great product!
New version of nos2x-fox (nostr signer Firefox addon) released!
This time it's just a couple of fixes.
As always, you can install it from the official marketplace or on your own with the xpi file.
More info: https://diegogurpegui.com/nos2x-fox/
Discussion
I saw some issues reported. I'll try to fix it today.
Do you mind sharing the issue you're having?