Oops, just re-read your post and missed a crucial bit on description!
Shame on me! So, it is not a Hoya.

Do you recall if the bloom was trumpet shaped or more tubular?

Do the leaves have any scalloping or serration to the edges or are they
completely smooth? Is the foliage thick and succulent or thin and
pliable?

There are very few house plants that will grow and flower in low light,
some may do okay for awhile, but eventually show signs of insufficient
light. Lack of bloom, weak and leggy growth. I have a Streptocarpus
that will tolerate low light for a while and sue to its succulent
nature is not too demanding of water.

Please reply here or contact me via e-mail and we'll see what we can
come up with.

You might also want to do a search at deserttropicals.com and see if
something listed there could be what you have.

Hemmaholic