Same issue here!! I set up a lot of short texts, so it's very annoying for me.
In other Apps, like Google Chrome for example, go to the menu bar and choose "Edit > Substitutions > Show Substitutions > Text Replacement" and deselect Text Replacement. This could turn off the text replacement feature.
But, there' no menu bar show with alfred's input box!
I can find the same menu with mouse right click on it, and can be disable temporary, but it won't save! Text replacement will re-enable after reboot.
Can't find a solution....