What's up with this courgette plant?

Not sure what's up with this plant, it's a 'Black Beauty' variety. Others (of different varieties) in the same container are fine and other Black Beauty plants in other containers are fine. All of the leaves are like the one in the photo to varying degrees.

Besides the weird leaf colouration the plant looks smaller than the others of the same variety. It's so far tried to produce one fruit but despite being manually pollinated the fruit is going a bit soft and rubbery and not growing at all.

Perhaps it's best to remove the plant and dispose of it?

 

Looks like scorch is it under glass.

 

Red spider mites would be my other guess, look for tiny mites and possibly webbing on the underside of the leaves.

 

Thanks but it's in the same location as other plants of the same variety which are just fine.

 

Thanks, just checked and no webbing and no spider mites (although I recall seeing just one yesterday).

 

It could perhaps be a virus, what do the new leaves look like in the centre of the plant.

 

The very small ones look okay but any leaf that's more than a couple of inches across is starting to look blotchy. Also any new, still forming tiny courgettes with unopened flowers look yellow (they should be green on this variety).

I'm happy to yank it out if people think that's the safest option, I have plenty.

 

I'd get rid of it if its not doing well just in case it infects the others.

 

Will do, thanks.