Please check our Content Security Policies you provide in Developer Cockpit. See also:
Number 14.) Set the Configurations > content-security-policy Value
Not seeing updates or changes that you make to Mendix applications in Mindsphere can also be connected to creating the deployment package.
When creating the deployment package Mendix will create it from the current version on the TeamServer. Meaning that if you create the deployment package before commiting your local changes to the Teamserver your changes will not be included.