Hang in there, let's just keep an eye on it and keep evaluating pictures. For what it's worth, I see what you're seeing, I almost had some seedlings go the wrong direction recently and they had the same sort of early yellow veining. They grow out of it as I just kept feeding them the correct ppm and pH.
For everyone else posting, I'm really confused why you don't believe OP's claims that previously seedlings have dudded and that these appear to be on the same track?? Why is everyone in here claiming there's no issue when this person is obviously reporting a 'failure to launch' from previous grow attempts? Kinda rude, honestly...