Brown pseudobulbs on Cyrtochilum meirax

[Octopus]

Hello everyone,
5 weeks ago I got this Cyrtochilum meirax for my birthday and since 3 weeks it gets brown pseudobulbs. Can anyone tell me what is wrong with it?

The first one looked very ‘dead’ so I removed it. I realised that it was a completely independent plant with roots that had obviously died.
Now the next pseudobulb has turned brown, I have carefully cut it off and disinfected it with cinnamon, but I am afraid that the ‘disease’ (?) will spread further.

Care: The plant is dipped once a week and sprayed twice a day. It is in a north-east facing window.

Does anyone know whether it is a disease / infection / ... and how I can save the plant? Unfortunately, it's my first ‘demanding’ orchid and I don't know if I'm making a mistake.

Best regards
Laura