Many thanks to you all for your valuable feedback and willingness to help. The keys from the channels with whose sid and ecm pid were the same, were overriding the keys from the channel I wanted to decrypt. It turns out that in SoftCam.Key, there were multiple channels using the same sid and pid (000B1FFF) as the channel that I wanted to decrypt.
I then deleted all of the biss keys that came included in SoftCam.key and left only the one biss key for the channel that I wanted to decrypt. I reached the conclusion that it couldn't be an oscam bug in both versions of oscam, especially after members in this forum confirmed that they were using this version of oscam and that it indeed was able to decrypt biss channels. After trying the latest version of oscam emu the biss channels would still not decrypt.
