Wrinkly patch on new Phal leaf

[turquoiseApples]

Hello,

I have a Schilleriana silver leaf hybrid and a Schilleriana (both very young) that has a wrinkly patch on the newest leaf. The affected area looks yellowish. On the hybrid, that area looks like the leaf is dehydrated but on the Schilleriana area below the leaf looks like it has been grazed on by a pest. None of my other plants seem affected at the moment but I have isolated these. The last image is of the Schilleriana. I would be happy to provide additional images or information.

I would appreciate any advice to help these little guys survive.

[Roberta]

Those patches look to me like sunburn. If growing under lights, maybe too close to light and got "heat burn" Not something that will spread, but I think that these need to be getting a bit less light.

[Dimples]

I agree that it looks like a heat/sunburn issue.

[Paphluvr]

Another vote for sunburn (i.e., too much light or heat).

[turquoiseApples]

A big thank you to everyone for responding and for your advice! That is interesting. I have never had a sunburn issue before. So, I did not even think of that as a possibility. They are not under grow lights but near a bright window. I moved them to an area with a little less light.

I am relieved that I don't have spider mites!