When running Jaspersoft Roadmap Timeline Report from Advanced Reporting or Reports and Jobs, in the output the months are out of order.
The issue can be intermittent and depend on user locale, or persistent.
Release: CODFSS99000-15.5-PPM SAAS FedRAMP-Sandbox-Small Environment
This is caused by DE48466, fixed in 15.6.1
If you're on lower version, consider upgrading, or if you will not upgrade for some time, contact Support for options