Sentry logging integration prevents sentry events being sent (Python)

I have a python 3 flask server running through WSGI. I have a config file that is imported by my api code that handles environment variables, and I set up sentry in this file. This is my code which is setup exactly as described in the sentry docs https://docs.sentry.io/platforms/python/logging/

        if sentry_dsn is not None:
            sentry_logging = LoggingIntegration(
                level=logging.INFO,
                event_level=logging.CRITICAL,
            )

            LOG.debug(f"Initialising sentry for environment {sentry_environment}")
            sentry_sdk.init(
                sentry_dsn,
                environment=sentry_environment,
                integrations=[sentry_logging],
            )
        else:
            LOG.warn("Sentry key not set up")

The problem is this does not send any events to sentry, in exception logs or even uncaught exceptions. I know that the DSN is correct because if I set up sentry like this, all uncaught exceptions as well as error and exception logs are sent to my sentry project:

        if sentry_dsn is not None:

            LOG.debug("Initialising sentry")
            sentry_sdk.init(sentry_dsn, environment=sentry_environment)
        else:
            LOG.warn("Sentry key not set up")

I’ve tried the setup with the debug=True setting in the sentry init and logs confirm that sentry intialises and sets up integrations. But when an event occurs that it should report, there is no log or anything recorded by sentry.

Any help would be appreciated

In your custom code you have raised the threshold level at which events are being sent, i.e. only logs with level critical will be sent to Sentry. Are you sure that the log level of those missing events is critical/fatal such that it is not filtered out?