There are multiple action bar bugs that appear to stem from the fact the game does not properly read the action bar under certain conditions:
1) When the player drag and drops an ability onto a NON-EMPTY action bar slot - The game seems to recognize BOTH the former ability and the new ability and attempts to use both, one at a time. This is only fixed by completely EMPTYING that action bar slot. This bug has a 100% replication rate at least for me (a.k.a. it happens every time).
2) When the player switches timeline - If the action bar on the PREVIOUS timeline contained abilities/consumables that the CURRENT timeline can use as a valid input, the game will not properly override that action bar slot and trigger a bug identical to #1 where it attempts to use both, one a time. This bug has a 100% replication rate at least for me (a.k.a. it happens every time).
For example, if you have “Sit and Rest” or “Tree of Life” bound to an action bar slot on Timeline A, but the action bar slot contains something different on Timeline B, when you switch to Timeline B it does not properly override that action bar slot because the game still recognizes those things as a valid player input. (Translation: this bug is likely happening across all action bar slots 100% of the time but in most instances it is being overridden because the game realizes that your Chronomancer on Timeline B should not be able to use “Full Heal”, etc.)