Most plants have these little yellow tips. This is particularly noticeable on the young leaves, as the yellow spots appear huge in relation to their leaf area. If you look closely, even your large leaves have bright tips. So don't worry
Some plants just do that for no reason at all, but you could give them a dose or two of soluble trace elements (available from any garden centre) to see if that helps, it certainly won't do them any harm, only good, either way.