Since the release of DragonFlight, the “Auto Self Cast” key seems to override specific targeting inside macros, such as using @cursor, @focus, @target. If you are holding the self cast key when the macro executes, your player always gets the spell cast on them.
As a side effect, healing addons (such as HealBot) end up wrongly casting spells on the player whenever the self cast key is held as a health bar is clicked.
WORKAROUND …
I got things working near perfect again. In the WoW Interface Options - Combat options, I had to turn off the “Self Cast” checkbox and also set the “Self Cast Key” to none. That resolved my HealBot targeting issues, but broke my macros that relied on auto self cast.
To solve that problem, any macro with conditions that ended with empty brackets [ ] had to be changed to end with [@player] to emulate auto self cast. Also, some spells on my button bar had to be changed into a macro so they could be written to do auto self cast.
For example, on my Priest, I had to create a macro for “Power Word: Life” like this …
#showtooltip
/use [@target, help] [@player] Power Word: Life
For a more advanced example, my shield macro casts on myself if ALT is being pressed, else on my target if its friendly, else on my focus if one has been set, else on me (as auto self cast).
#showtooltip
/use [mod:alt, @player] [@target, help] [@focus, exists] [@player] Power Word: Shield
I only made these changes on my main character for now, in hopes that Blizzard restores the old behavior by the time I get to my alts.