Yes. While I have not planted ground covers in my wood chip mulches I have had wild strawberries root in, and grow very thick in that mulch.

Vinca vines work well for me and the variegated ones are really nice looking and mostly evergreen. I almost consider them weeds though because although they look nice, they are invasive. Variegated vinca vines look their best in shade, but I have a group in ALL day sun and they look good too, the leaves are just a little bit smaller and more compact (but the leaves are much bigger than the more common perrenial vincas). Good luck! -Alex

When were these plants planted? Except for annuals, which have only a single growing season to complete their entire life cycle, perennial plants like groundcovers need time to establish before they they start a significant spread. And groundcovers spread by different means - those that spread rhizomatously are not fazed at all by mulches, even thick ones. But those that root as they go or self seed may be slowed by a lot of mulch. Since both your choices fit within this second category, their development could be slowed by a heavy mulch but maybe you just need to give them sufficient time to settle in and establish.

Personally I would plant mint. Lots of it, in all possible flavours. I understand you don't want to care for that corner much, in which case you need something that looks good all the time, not just two months a year. You can have a mix of winter cyclamen and hellebores, spring lilly of the valley (I have small kids and they are smart enough not to touch anything I tell them is poisonous), summer moss, autumn cyclamens (different than winter ones). However all this requires some maintenance, much more than mint :D Why not place a few aromatics? Like celery, parsley and a few pots of mint? ;) Also spinach, peas and lettuce would love to grow there. Or you could go for a trellis on the wall and let vinca grow on it, one with gorgeous leaves. I have a full north little space and the previous owners had the vinca and trellis. It looked nice but I preffered to reduce it in size and plant small pansies and many types of hellebores. It makes for a gorgeous front autumn and winter garden, less gorgeous in spring and summer.