backend columns do not show custom fields anymore

Hi,

Could you provide some screenshot to illustrate the issue because I don't understand what you're talking about ?

Hi,

Note that the custom fields will only be available there if the "backend listing" setting of the custom order field is activated.
Can you confirm that this is the case ?

Hi,

Thanks for the detalis. We've looked into it and it's a bug introduced by changed we added in the 5.0.1 to improve the search capabilities on the orders listing. We've added a patch to fix it.
Download again the install package of the 5.0.2 on our website and install it on yours and you'll have the patch.