How to disable the desktop correctly?

Hi, when I installed Debian Trixie, I set it to display the desktop 
manager after boot so I could log on straight to the Mate desktop with 
Orca's help. But now, I'd like to disable the desktop login at boot, and 
enable fenrir, so I can log into a pure console with speech after boot. 
After installing Fenrir, I tried:
systemctl disable lightdm
systemctl enable fenrir
but it hasn't worked. After rebooting, I was without any speech. I tried 
without speech to log in and call fenrir, and even espeakup, but speech 
didn't come at all. Curiously, before disabling lightDM, while still at 
mate-terminal, I was able to successfully call fenrir, then change to a 
pure console and have speech, so Fenrir is definitely working. It 
appears not to work only when I call it without entering into the 
desktop first. Unfortunately, after disabling lightDM, calling systemctl 
start lightdm from a pure console hasn't worked, or at least, it didn't 
bring speech. I needed to boot from Debian installer and re-enable 
lightDM from rescue mode.

So, what is the correct way to disable the desktop and enable fenrir to 
have speech at boot, please?

Thanks,
Cleverson