Is this fungal?

Thanks Scarlet, yeah they are in pots, about 18”-2’ tall. Missed getting them in the ground last year because of lockdown but hopefully get them in this autumn. Think you and the boss have hit on it...lack of water.

Just to say I’ve moved the saplings into a much more shaded area, kept them watered and I’m pleased to report new leaves appearing! Thanks for all the advice.