You have reported an issue whereby you are noticed an issue in the SLA Timeline after upgrading the SNOW COVEA instance .
The SLAs which are "out of time" appear in red from the start, and they were green, then orange, then red, depending on the different thresholds crossed (see attachment).
You request to keep the history of SLA incident states/color according to the states by which it happened.
Customer had several modified script includes which were impacting this behavior.
2 copies of task sla:
https://xxxx.service-now.com/nav_to.do?uri=sys_script_include.do?sys_id=10d0c7590a0a2c394e2b1766a6e5fbad inactive OOB
2 copies of SLACalculatorNG
https://coveadev.service-now.com/nav_to.do?uri=sys_script_include.do?sys_id=9ba81e3d0a0a2c513f0ea765abd97c40 inactive OOB
Customer had inactivated the OOB script and was using Customized files.
Issue was resolved after merging with OOB.
They have modified these customized files to include the OOB code that has been missed out while still keeping their customizations.
This has now resolved the issue.