You are probably doing nothing wrong. Maybe this is not a good choice of orchid to grow in your kitchen. Where in the world is your kitchen and what are the temperatures there, how far from the windows and so on?

Wisconsin - This winter the warmest it has been (outside of the rare occassion that I cook) was probably 65F. It was a bit drafty this year. I keep it under the mounted sink light. The room has southern/east exposure. My other orchids have first dib on the window ledges.

You must use a lot of energy to keep warm. But heated air most of the time is too dry. But I do not have any remedies as I live in humid Florida so I am not faced with that issue. Get a hydrometer to measure your humidity in your kitchen. Then we can either eliminate humidity or know it is the problem...

If you know any orchid growers nearby they would be a good source. If the distance is modest consider joining a local orchid society. A pleasant experience and a lot to learn from friendly people that like to talk about orchids...They have answers on dealing with dry air...

potting advice always needs to be local...

All you can do with an orchid that is not widely grown is read up on where it grows in the wild and try and copy those conditions. A starting point is your other orchids, if they are growing well you can try to place the Restrepia relative to those.... but be aware that you would need many different growing places to grow every type of orchid.

I have one Restrepia and it is not happy. It is in a glass-house. Low down, just above bench level in the shadiest place in that house. I suspect it would be happier if the outside climate was something like San Francisco rather than here.

I don't grow Restrepia, but I know people that do and I love in Northeast Ohio. So I figure my climate is pretty similar to yours. Humidity is likely going to be your main issue. The people in my society that grow this genus either grow in a green house or they grow in a vivarium or similar. Their humidity levels are at the lowest 60%, which is difficult, and likely inappropriate, for a home/windowsill growers. Maybe you could try growing in the a larger glass jar or hobby terrarium?

Thanks Darlene, shavedmonkey & arthurm. I will try and increase the humidity. I'm just happy that it still grows like a weed.