diff --git a/.github/workflows/compatibility_tests.yml b/.github/workflows/compatibility_tests.yml
index 0f3885958..4d2691418 100644
--- a/.github/workflows/compatibility_tests.yml
+++ b/.github/workflows/compatibility_tests.yml
@@ -7,6 +7,10 @@ on:
     branches:
       - main
 
+  # For debug - uncomment below to run on all PRs
+  pull_request:
+    branches: "*"
+
 env:
   JEST_ENV: prod
 
@@ -28,13 +32,14 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
+        # note: The `macos-latest` is latest Catalina version, and not Big Sur. So we explicitly ask for Big Sur (`macos-11`)
         os: [ubuntu-latest, macos-latest, macos-13]
-        python-version: ["3.10", "3.11", "3.12"]
+        python-version: ["3.10", "3.11"]
         cellxgene_build: [main, latest]
         # add anndata pinned version test for subset of matrix configurations,
         # in order to reduce matrix cross-product explosion
         include:
-          - python-version: 3.12
+          - python-version: 3.11
             cellxgene_build: latest
             # TODO: dynamically use the literal version in requirements.txt,
             # to avoid having to update this in manually in the future
@@ -95,7 +100,7 @@ jobs:
           # keep same pip pkg versions as in the cxg release
           sed -i'' -e 's/-r requirements.txt//' server/requirements-dev.txt
           pip install -r server/requirements-dev.txt
-          pip install --force-reinstall numpy==2.0.1 numba>=0.60.0 pandas flatbuffers==2.0.7
+          pip install --force-reinstall numpy==2.0.1 numba>=0.60.0 pandas
       - name: Install anndata version per matrix variable
         run: pip install anndata${{ matrix.anndata_version }}
       - name: Install node