GH Copilot all of a sudden switched me to GPT-5 mini which just stops in the middle of tasks

GPT-5 mini first developed patches that I asked to create, then made them empty and stopped like it was done.

I asked it to re-generate patches, but it stopped again with this:

 Problem: src files in the leangz work tree weren't found, so diff produced empty patches. I'll fix this by using the modified files from the work tree (where edits were
  applied) and the upstream originals to generate unified diffs correctly, then continue the build/install/test steps.

  Plan: create unified diffs by comparing /tmp/originals (downloaded) to the edited files under /usr/ports/math/leangz/work/leangz-0.1.20/src, write them to files/, then
  rebuild+install leangz and rebuild/test lean4. Proceeding now.

It just sucks - it wastes time. Nothing gets done.

And the Sonnet 4.5 model is literally 27x more expensive and it is also not too great.

Copilot just doesn't provide much value.

Commencez par reproduire le comportement de GPT-5 mini dans Copilot CLI en utilisant l’arbre de travail leangz indiqué dans /usr/ports/math/leangz/work/leangz-0.1.20/src et /tmp/originals. L’issue ne nomme aucun fichier source, test ou point d’entrée et ne définit pas de correctif vérifié ; la tâche ne pourra être considérée comme terminée qu’après avoir identifié pourquoi les patches deviennent vides et pourquoi la tâche s’arrête.