My targetoftarget window does not react to features tied to Variable: Unit in Set --> DeadOffline filterset. I have isolated all other factors and determined it is probably a bug with "targetoftarget" specifically, as other unitframes work correctly using the same design.
Attached is my lua file for targetoftarget window. When alive, the backdrop is two-color blend from black to red by HP variable. When dead, the backdrop is supposed to turn grey. However, it stays red since it does not recognize the unit is dead (however, it recognizes in the paint preview).