Describe the bug
Flame Dart timer is off.

Do you have an error log of what happened?
https://gist.github.com/Molkree/d68f950192479afdc70897a2fd2e1966

Screenshots

Did you try having DeadlyBossMods as the only enabled addon and everything else (especially something like ElvUI) disabled?
No.

Which version of DeadlyBossMods are you using?
Latest alpha at the moment of fight.

Was it working in a previous version? If yes, which was the last good one?
No idea.