Cucamelon transplating

Has anyone had issues with transplanting Cucamelons from pots into open ground? Ive tried twice and both times they (the Cucamelons) have collapsed and died.

Is it worth perhaps planting their current pot into the ground? Ive heard they like being rootbound.

 

Only tried them once and then I grew them in the greenhouse, so not tried them outside.
I think they like it warm so it might be a bit early.

 

I started mine off in small pots then thinned them out. Once I had around 6 or so, I placed 3 into a large pot outside under a trellis and 3 next to them but in the ground. My ground transplanted ones are struggling, whereas those left in a large pot have this week given me my first handful of harvest.

I think going forwards, I will stick to transplantation into pots only, but maybe extend from one pot to a handful.

Good luck, I hope all is not lost