Chris Llewellyn admitted it was a case of deja vu after seeing his Under-21 side slip to a 2-1 defeat against Cardiff at the Liberty.
The home side took a deserved lead midway through the first half when Modou Barrow finished well from Kenji Gorre's pass.
Chances came and went for the hosts as both Gorre and Marvin Emnes - who completed 90 minutes after returning from injury - spurned opportunities to extend the lead.
But Cardiff hit back to take all three points thanks to a Rhys Healey double - the winner coming with five minutes left to play as the Swans let slip a one-goal lead for the second game in succession.
"Overall, it's disappointing really," said Llewellyn. "It's the same old thing where we have taken the lead and let it slip.
"It happened at the end of last season and that has continued in the early part of this year.
"We created a lot of chances again and could have scored another two or three in the second half.
"But when you don't take your chances the opposition gains confidence and Cardiff punished us.
"The lads have to learn, and quickly. We move on, we have another game next week and hopefully we can put it right."
Meanwhile, Modou Barrow caught the eye once more as he scored his second goal in three outings since arriving from Swedish side Ostersunds.
"It is something we have worked on in training, trying to get Modou to come in off the flank and that's two goals he has scored now," said Llewellyn.
"It was disappointing to lose him to injury but these things happen. The more he is with us the more confident he'll get and if we can keep him fit then I'm sure he'll score a lot more goals for us."