When the SWAPP launches, a popup appears with a message saying "ERROR: Third party cookies must be allowed for domain 'https://spotfire.your-company.com'".
Starting in February 2020, Chrome 80 introduced the SameSite policy for cookies (read more here). This new policy aims at securing cookies cross-domain and block third-party cookies.
Spotfire soon implemented this feature which can cause mashup application to stop working, as described on their support site.
To fix this issue, you need to change the SameSite attribute on the server and set it to "None". See TIBCO Documentation for more details.