Some words are not playing sound in utau.

[Fudgetusk]

I use Etsuko Akane 2019 vccv english voicebank. For example when I write the word "bu" it plays the sound, but when I want to write "but" it mutes. By the way I don't use computer. I use exagear windows emulator on my android phone. Please check this video that I uploaded to better understand what I'm saying.
Anyway I also used the DeepVocal synthesizer and exactly the same problem happens.

 

[Kiyoteru]

You cannot enter full English words in UTAU. You must input parts of syllables phonetically. For VCCV English voicebanks, refer to this tutorial.

 

[Fudgetusk]

I didn't know that. Thank you.