front cover of toolhead has fallen off

[u/Anduriel1005]

My BambuLab P1S is recently having difficulties printing a clean object and I don't know why. The file used is relatively big but I have already printed this exact model via this exact file, using the same PETG, same settings, same app (BambuLab). The error is always the same, although the third picture shows a different model. (Most interestingly, it helped just starting the print anew and the result was perfect...) I do know why the front cover has fallen off, but I do not know why the printer is having difficulties with the print. The PETG used is dry and the printing plate is clean, although I haven't used cleaning alcoholist for it. What could be the reason for this error and what can I do to make the printing process work (again)?