That is easy, because the Eucharis is equipped with the following sensors.
Ks-MIES-E3013 Subspace Mass Detector
Range of 20 LY
Faster than light
Ks-MIES-E3022 Hyperspace Tracking
Range of 20+ LY
Faster than light detection
The E3013 would track an uncloaked CFS ship, and the E3022 would detect the fold ship approaching.
We had no notice except when the scout ship was dropping out of fold, hence our sensors are obviously not operating according to specs,
And we similarly had no advance warning of the earlier NMX fleet arrive, ergo same, our equipment is not working. Because neither time were the ships arriving in cloak.