diff --git a/.github/workflows/cache.yml b/.github/workflows/cache.yml
index f968aa655..fad0ededd 100644
--- a/.github/workflows/cache.yml
+++ b/.github/workflows/cache.yml
@@ -2,6 +2,7 @@ name: Build Cache [using jupyter-book]
 on:
   push:
     branches:
+      - cache_test_1
       - main
 jobs:
   tests:
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 638eac2b3..324d22854 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -41,7 +41,7 @@ jobs:
         uses: dawidd6/action-download-artifact@v6
         with:
           workflow: cache.yml
-          branch: main
+          branch: cache_test_1
           name: build-cache
           path: _build
       # Build Assets (Download Notebooks and PDF via LaTeX)
@@ -65,7 +65,7 @@ jobs:
           cp -u _build/jupyter/*.ipynb _build/html/_notebooks
       # Build HTML (Website)
       # BUG: rm .doctress to remove `sphinx` rendering issues for ipywidget mimetypes
-      # and clear the sphinx cache for building final HTML documents.
+      # and clear the sphinx cache for building final HTML documents. 
       - name: Build HTML
         shell: bash -l {0}
         run: |
diff --git a/environment.yml b/environment.yml
index f60099b5e..777c062a3 100644
--- a/environment.yml
+++ b/environment.yml
@@ -13,7 +13,7 @@ dependencies:
     - sphinx-tojupyter==0.3.0
     - sphinxext-rediraffe==0.2.7
     - sphinx-exercise==0.4.1
-    - sphinx-proof==0.2.0
+    - sphinx-proof==0.1.3
     - ghp-import==1.1.0
     - sphinxcontrib-youtube==1.1.0
     - sphinx-togglebutton==0.3.1
diff --git a/lectures/_config.yml b/lectures/_config.yml
index ecd808f0f..84d407d7e 100644
--- a/lectures/_config.yml
+++ b/lectures/_config.yml
@@ -45,7 +45,6 @@ sphinx:
       width: 80%
     nb_code_prompt_show: "Show {type}"
     suppress_warnings: [mystnb.unknown_mime_type, myst.domains]
-    proof_minimal_theme: true
     # -------------
     html_js_files:
       - https://cdnjs.cloudflare.com/ajax/libs/require.js/2.3.4/require.min.js