New update: I rebuilt freefem++ from source using the instructions from: https://wiki.debian.org/SimpleBackportCreation The issue disappeared. The PC used to rebuild the package is the one for which freefem++ crashed before (2 CPUs).
New update: I rebuilt freefem++ from source using the instructions from: https://wiki.debian.org/SimpleBackportCreation The issue disappeared. The PC used to rebuild the package is the one for which freefem++ crashed before (2 CPUs).