diff --git a/changelog/6629.bugfix.md b/changelog/6629.bugfix.md
new file mode 100644
index 000000000000..43063d142356
--- /dev/null
+++ b/changelog/6629.bugfix.md
@@ -0,0 +1 @@
+Fixed a bug that occurred when setting multiple Sanic workers in combination with a custom [Lock Store](lock-stores.mdx). Previously, if the number was set higher than 1 and you were using a custom lock store, it would reject because of a strict check to use a [Redis Lock Store](lock-stores.mdx#redislockstore).
diff --git a/rasa/core/utils.py b/rasa/core/utils.py
index 289de4900934..ad7443925bc3 100644
--- a/rasa/core/utils.py
+++ b/rasa/core/utils.py
@@ -32,7 +32,7 @@
 
 # backwards compatibility 1.0.x
 # noinspection PyUnresolvedReferences
-from rasa.core.lock_store import LockStore, RedisLockStore
+from rasa.core.lock_store import LockStore, RedisLockStore, InMemoryLockStore
 from rasa.utils.endpoints import EndpointConfig, read_endpoint_config
 from sanic import Sanic
 from sanic.views import CompositionView
@@ -450,25 +450,29 @@ def replace_decimals_with_floats(obj: Any) -> Any:
     return json.loads(json.dumps(obj, cls=DecimalEncoder))
 
 
-def _lock_store_is_redis_lock_store(
+def _lock_store_is_multi_worker_compatible(
     lock_store: Union[EndpointConfig, LockStore, None]
 ) -> bool:
+    if isinstance(lock_store, InMemoryLockStore):
+        return False
+
     if isinstance(lock_store, RedisLockStore):
         return True
 
-    if isinstance(lock_store, LockStore):
-        return False
-
     # `lock_store` is `None` or `EndpointConfig`
-    return lock_store is not None and lock_store.type == "redis"
+    return (
+        lock_store is not None
+        and isinstance(lock_store, EndpointConfig)
+        and lock_store.type != "in_memory"
+    )
 
 
 def number_of_sanic_workers(lock_store: Union[EndpointConfig, LockStore, None]) -> int:
     """Get the number of Sanic workers to use in `app.run()`.
 
     If the environment variable constants.ENV_SANIC_WORKERS is set and is not equal to
-    1, that value will only be permitted if the used lock store supports shared
-    resources across multiple workers (e.g. ``RedisLockStore``).
+    1, that value will only be permitted if the used lock store is not the
+    `InMemoryLockStore`.
     """
 
     def _log_and_get_default_number_of_workers():
@@ -496,12 +500,12 @@ def _log_and_get_default_number_of_workers():
         )
         return _log_and_get_default_number_of_workers()
 
-    if _lock_store_is_redis_lock_store(lock_store):
+    if _lock_store_is_multi_worker_compatible(lock_store):
         logger.debug(f"Using {env_value} Sanic workers.")
         return env_value
 
     logger.debug(
         f"Unable to assign desired number of Sanic workers ({env_value}) as "
-        f"no `RedisLockStore` endpoint configuration has been found."
+        f"no `RedisLockStore` or custom `LockStore` endpoint configuration has been found."
     )
     return _log_and_get_default_number_of_workers()
diff --git a/tests/core/test_utils.py b/tests/core/test_utils.py
index 3e9160739003..e21a60e41ea3 100644
--- a/tests/core/test_utils.py
+++ b/tests/core/test_utils.py
@@ -15,6 +15,10 @@
 from tests.conftest import write_endpoint_config_to_yaml
 
 
+class CustomRedisLockStore(RedisLockStore):
+    """Test class used to test the behavior of custom lock stores."""
+
+
 def test_is_int():
     assert utils.is_int(1)
     assert utils.is_int(1.0)
@@ -132,8 +136,10 @@ def test_replace_decimals_with_floats(_input: Any, expected: Any):
         (5, "in_memory", 1),
         (2, None, 1),
         (0, "in_memory", 1),
+        (3, "tests/core/test_utils.CustomRedisLockStore", 3),
         (3, RedisLockStore(), 3),
         (2, InMemoryLockStore(), 1),
+        (3, CustomRedisLockStore(), 3),
     ],
 )
 def test_get_number_of_sanic_workers(
@@ -168,16 +174,19 @@ def test_get_number_of_sanic_workers(
         (EndpointConfig(type="redis"), True),
         (RedisLockStore(), True),
         (EndpointConfig(type="in_memory"), False),
-        (EndpointConfig(type="random_store"), False),
+        (EndpointConfig(type="custom_lock_store"), True),
         (None, False),
         (InMemoryLockStore(), False),
+        (CustomRedisLockStore(), True),
     ],
 )
-def test_lock_store_is_redis_lock_store(
+def test_lock_store_is_multi_worker_compatible(
     lock_store: Union[EndpointConfig, LockStore, None], expected: bool
 ):
     # noinspection PyProtectedMember
-    assert rasa.core.utils._lock_store_is_redis_lock_store(lock_store) == expected
+    assert (
+        rasa.core.utils._lock_store_is_multi_worker_compatible(lock_store) == expected
+    )
 
 
 def test_read_endpoints_from_path(tmp_path: Path):