What is the problem?
The octoprint server shut down while printing, the pi didn't turn off
What did you already try to solve it?
Looked through the logs, and haven't been able to find any reasons to why has this happened
serial.log or output on terminal tab at a minimum, browser error console if UI issue ... no logs, no support! Not log excerpts, complete logs.)
Additional information about your setup
OctoPrint version, OctoPi version, printer, firmware, browser, operating system, ... as much data as possible
OctoPrint 1.4.0 running on OctoPi 0.15.0PE (Prusa Edition)
Prusa i3 Mk3s MMU2s
Plugins: TouchUI, Prusa MMU2 Select Filament