Dry/Wet Vacuum Shuts Down After A Few Seconds

I have a wet vacuum that stops after a few seconds and says “install the roller,” even when the roller is properly installed.

• The roller spins freely and is seated correctly.
• Bearings were slightly dirty but have been cleaned and lubricated.
• The motor shaft spins when powered, both with and without the roller.
• Applying extra friction to the roller does not prevent the error.
• There are no sensors on the roller itself, or any where around it.

Despite the roller being installed and spinning, the vacuum consistently displays the “install roller” message.

The model is "Roidmi NEO".