diff --git a/.github/workflows/demos_ltr_latest.yml b/.github/workflows/demos_ltr_latest.yml
index 695c95e5c6c0..28b786b53e2f 100644
--- a/.github/workflows/demos_ltr_latest.yml
+++ b/.github/workflows/demos_ltr_latest.yml
@@ -5,12 +5,11 @@ on:
     inputs:
       git-ref:
         description: Git Ref
-        default: engine-3.16  # FIXME: point to ltr
+        default: engine-3.16  # TODO: point to ltr
         required: true
   push:
-    # FIXME: it would be better to point to ltr and latest
-    # branches: [ demos_ltr_latest, engine-3.16, engine-3.17, engine-3.18 ]
-    branches: [ demos_ltr_latest ]
+    # TODO: it would be better to point to ltr and latest
+    branches: [ engine-3.16, engine-3.17, engine-3.18, engine-3.19]
 jobs:
   demos:
     runs-on: ubuntu-latest
@@ -30,7 +29,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           ref: ${{ github.event.inputs.git-ref }}
-      - name: Set up Python 3.10
+      - name: Set up Python 3.10  # for compatibility with engine 3.16
         uses: actions/setup-python@v5
         with:
           python-version: "3.10"
@@ -40,21 +39,18 @@ jobs:
           pip install --default-timeout=100 -U pip
           pip install pydata-sphinx-theme
       - name: Install OpenQuake engine
-        #    env:
-        #      GITHUB_DEF_BR:  ${{ github.event.repository.default_branch }}
-        #      GITHUB_REF:  ${{ github.ref }}
         run: |
-          if [ -z "$GITHUB_INPUT_REF" ]
+          if ${{ github.event_name == 'pull_request' }}
           then
-              echo " Is not a workflow_dispatch RUN, use: $GITHUB_DEF_BR "
-              python install.py devel --version ${GITHUB_DEF_BR}
+              echo "It is a pull request; use the corresponding branch: ${GITHUB_HD_REF}"
+              python install.py devel --version ${GITHUB_HD_REF}
           else
-              echo " Is a workflow_dispatch RUN, use: $GITHUB_INPUT_REF "
-              GITHUB_BR=`echo ${{ github.head_ref }}`
+              echo "It was triggered manually; use the selected Git Ref: $GITHUB_INPUT_REF "
               python install.py devel --version ${GITHUB_INPUT_REF}
           fi
-      - name: Run demos and upload to ci.openquake.org if not workflow_dispatch
-        if: github.event.inputs.git-ref == ''
+      - name: Run demos and upload to ci.openquake.org
+        # uncomment the line below to avoid running this part when triggering the action manually
+        # if: github.event.inputs.git-ref == ''
         shell: bash
         env:
           DOCS_SSH: ${{ secrets.DOCS_ARTIFACTS }}
@@ -70,14 +66,13 @@ jobs:
           oq dump /tmp/oqdata.zip
           oq restore /tmp/oqdata.zip /tmp/oqdata
           helpers/zipdemos.sh $(pwd)/demos
-          echo " Check if this is a pull request or not"
-          if [ -z "$GITHUB_HD_REF" ]
+          if ${{ github.event_name == 'pull_request' }}
           then
-              echo " Is not a pull request, use branch: $GITHUB_DEF_BR"
-              GITHUB_BR=`echo ${{ github.event.repository.default_branch }}`
+              echo "It is a pull request; use the corresponding branch: ${GITHUB_HD_REF}"
+              GITHUB_BR=${GITHUB_HD_REF}
           else
-              echo " Is a pull request, use branch: $GITHUB_HD_BR"
-              GITHUB_BR=`echo ${{ github.head_ref }}`
+              echo "It was triggered manually; use the selected Git Ref: $GITHUB_INPUT_REF "
+              GITHUB_BR=${GITHUB_INPUT_REF}
           fi
           echo "BRANCH set to $GITHUB_BR"
           gpg --quiet --batch --yes --decrypt --passphrase="$DOCS_SSH" --output ./.deploy_rsa ./.deploy_docs.enc