I’ll call it sp. Sentang then. I think they were mixed up in the shop’s tank. First I got two males, of which the other one was much more colourful. That one died without clear reason so I bought a new one which appeared to be a female. The female has different ventrals. But, since it is a female, I can’t say what it is. I bought them as deissneri indeed, so I didn’t know what I was buying exactly. The catch locality was given as “Borneo” on the label, not Sumatra, surprisingly.
I hope the breeding problems with the real deissneri will be solved soon, before they go completely extinct.