Port Vale boss Dean Glover was left to bemoan a lack of consistency following his side's 3-1 defeat at home to Gillingham.
The Valiants had been unbeaten in their previous two games before producing a below-par display on Tuesday evening.
"We are here again. We can't seem to put two results together at home and it's very frustrating," said Glover.
"Our concentration levels are just not good enough. We defend okay for so long and then players switch off.
"It's another disappointment, but I have to give Gillingham some credit because they played well and are making progress."