diff --git a/backends/tfhe-cuda-backend/cuda/src/crypto/fast_packing_keyswitch.cuh b/backends/tfhe-cuda-backend/cuda/src/crypto/fast_packing_keyswitch.cuh
index f3fe542dd9..d78dcb37a5 100644
--- a/backends/tfhe-cuda-backend/cuda/src/crypto/fast_packing_keyswitch.cuh
+++ b/backends/tfhe-cuda-backend/cuda/src/crypto/fast_packing_keyswitch.cuh
@@ -31,8 +31,8 @@ __host__ inline bool can_use_pks_fast_path(uint32_t lwe_dimension,
                                            uint32_t polynomial_size,
                                            uint32_t level_count,
                                            uint32_t glwe_dimension) {
-  // TODO: Generalize to level_count > 1 by transposing the KSK
-  return level_count == 1;
+  // TODO: activate it back, fix tests and extend to level_count > 1
+  return false;
 }
 
 // Initialize decomposition by performing rounding
diff --git a/ci/slab.toml b/ci/slab.toml
index 1a1d8e41e0..eeacfb2a11 100644
--- a/ci/slab.toml
+++ b/ci/slab.toml
@@ -31,7 +31,7 @@ instance_type = "m6i.4xlarge"
 [backend.hyperstack.gpu-test]
 environment_name = "canada"
 image_name = "Ubuntu Server 22.04 LTS R535 CUDA 12.2"
-flavor_name = "n3-RTX-A6000x1"
+flavor_name = "n3-L40x1"
 
 [backend.hyperstack.single-h100]
 environment_name = "canada"