<target.var.Modifier> in a damage mechanic causes Failed to Process placeholder

Summary

When using targetscoped variables in a damage mechanic a Failed to process placeholder <target.var.Damagemod|1> in xPlaceholderString{'2*<target.var.Damagemod|1>'} is thrown.

Steps to reproduce

preparation:

Item:

placeholderInDamageAxe:
  Material: STONE_AXE
  Skills:
  - skill{skill=placeholderInDamage} @trigger ~onInteract

Skill:

placeholderInDamage:
  Skills:
  - setVar{name=target.Damagemod;value=50;type=FLOAT;duration=100}
  - damage{amount=2*<target.var.Damagemod|1>} 

Execution: Interact with a mob using the placeholderInDamageAxe.

Current behavior

After interacting the mob takes damage, but not the amount one would expect(8 damage opposed to 100), and the server throws: https://pastebin.com/KUf4eWWk

Intended correct behavior

The damage should be 100 and there should be no error.

Debug log snippet

Debug 5 log: https://pastebin.com/B7WFaCC2

the log from logs/errors: https://pastebin.com/CGZDj5q9