Seems too small to be
Vandopsis gigantea and too large to be
Hygrochilus parishii ... and both plants have naturally very dark green leaves (although that is culture dependent and a bad indicator, I know) that are wider compared to their overall length than the leaves on your plant. My guess would be a young
Rhynchostylis ... not
gigantea, the leaves are not wide enough, not
coelestis, the leaves are not curved enough ... I think it could be a young
Rhynchostylis retusa.
If you could photograph the tips of the leaves, that would be quite helpful.
Rhynchostylis have very retuse (hence the species name

) and unequally lobed leaf tips, whereas in
Vandopsis and
Hygrochilus the tips are more equally lobed.
This "guessing game" is strangely exciting.

Can't wait to see the fully open flowers now!