Perhaps a galloping case of edema (also spelled oedema.) If so, not a disease, but environmental.

Thanks for the thought about edema.
Whatever it is, it hasn't gotten worse (i.e., the plant is not now a dry husk). Some of the leaves are still blighted but flowers are blooming and new growth is coming. So I'm still holding out hope.

If it is edema then probably the greenhouse is a bit too humid. Once weather warms up a bit more I can try moving it outside.

It's edema for sure. Will grow out of it

Will it effect other plants?

The soil may be too wet or too moisture-retentive. What medium are you using?

Im pretty sure its to wet, we have a lot of humitity.

Thank you

Whether it affects other plants depends on what the appropriate moisture levels are for those species and how sensitive they are to excess moisture in the air and soil. It's not a contagious condition.