VoiceOver on the log in screen

While I do not know which Mac computer you are using, or what version of macOS, I can tell you that my old MacBook Pro, currently running macOS 12 (Monterey), has this issue as well. I have to manually enable VoiceOver every single time I reboot. Not sure if there are any workarounds for this, but yeah, it's not really anything new. 🙂

HTH.

I stand by my previous statement though, it's an old issue. 😛

Do you have FileVault enabled by any chance? Because the experience differs when you do, as only a tiny portion of the filesystem required to decrypt everything is unencrypted, although still digitally signed. When you have FileVault enabled, a rudimentary log-in screen is displayed right after the boot chord, and the screen-reader available there is a stripped-down version of VoiceOver.

One thing I'm noticing since updating to macOS 26.3, meaning the previous stable version since currently we are on 26.3.1, is that often VoiceOver fails to recognize the authentication prompt, stating that there's nothing in focus, and not listing any open applications or windows even when you press VO+Fn+F1 or VO+Fn+F2, thus requiring cycling the screen-reader. This happened on both my M1 and M4 Max Macs, so I'm pretty sure that it's not a specific case especially since I wiped my M1 Mac pretty recently.

If you don't have FileVault enabled then I cannot talk since I always run my Macs on FileVault, and only took a short break after going blind until I learned that the boot process was still accessible with some beeps hinting at the current state when FileVault was enabled, which evolved to a static recorded utterance from the Alex voice at some point, and finally to a fully-blown screen-reader on modern Macs.

To check whether FileVault is enabled, you can use the fdesetup command on Terminal, as follows:

jps@alpha ~ % fdesetup status
FileVault is On.

Alternatively, you can also go to System Settings -> Privacy & Security, and search for the FileVault switch on the right pane.

Another thing to check is that VoiceOver is configured to automatically start at login in Lock Screen Settings. To do this, go to System Settings > Lock Screen, click Accessibility options, and make sure the "VoiceOver" switch is on.

HTH

How file vault behaves also largely depends on the mac moddle. If intel, you'll just get a, username, password, prompt, but on apple m1 etc macs you will be able to move through the screen with arrows or tab. Also having 2 macs oddly enough, the 2018 intel moddle does have this bug even though i'm pretty sure accessibility on login screen is on, however this is not happening in my m3 mac. Might be intel specific, maybe.
As far as voiceover getting stuck in the authentication screen and not reading anything when file-vault is on, do a mouse click, vo shift space, that'll bring you to the login screen.

I am not 100% sure about this, but apple mention something along those lines in the user guide and from my own experience.
TLDR I believe if you or somebody else manually turn voiceover off on the login screen, or a similar condition, VO will remain off on the login screen until you re enable it from the system settings like you did.
Again, not 100% sure but I am sure there's something very close to that at least.