No idea if it’s a bug, for me is definitely an unexpected behaviour:
Basically I control the Symbol timeline from outside and in the end I reverse the direction, but when reaches again the beginning probably the Symbol index doesn’t remain to 0. Check the project to have a better idea of what I’m trying to explain!
TIMELINE RESET WORKAROUND
I also found a workaround, I move manually the internal Timeline to 0:
I am sure the problem is you are telling the Main Timeline of the Scene to play in reverse, Which means it will replay the Main timeline of the Symbol (Action) when it gets back to the beginning.
If you set your play reverse Action on the Symbol Actions then you will be telling the symbol to play in reverse without it restarting when it gets back to it’s beginning.