Tool starts print without filament being loaded
I unloaded filament from Tool 2 but did not reload filament into Tool 2. I then started a print file sliced for a single tool expecting it to select Tool 1. Tool 2 was still in the carriage when I started the print, as the machine had left it there following filament change. The printer went through the full pre-print routine with Tool 2 still in the carriage. It then started the print, even though there was no filament in the tool. At no time did I get a warning that there was no filament in Tool 2.
I would have expected the filament sensor to recognize the absence of filament and at least asked for filament to be loaded before the print started.
Factory assembled dual head Prusa XL with firmware 4.7.1. File sliced using PrusaSlicer 2.6.0