Strange behavior kerning when working with layers

I am working on a layered typeface. To be able to see the results, I am working with colored layers.

I noticed that depending on how you show or select the layers, sometimes kerning is being disabled. When you check every layer independently, the kerning is there.

Enforce compatibility check is on.

Anyone an idea ?

Can you send me the font and explain exactly what you are doing?

Yes !

Support@… if I am correct ?

Yes.

Did you find something ?