Interesting, so the spoofing is only active during attacks? That explains the short duration.
I am wondering what changed though, since this hasn't happened before in the previous 4 years. More spoofing installations maybe? Higher radio transmitter power?
I'm also very curious, do you have any technical mitigations for this to be able to use your GPS devices? Or is it now just a fact of life?
Sorry for what you are going through.