HDDL parser doesn't support ordering subtasks together when those subtasks are actions about hypertension HOT 2 CLOSED

Not sure which state you are referring to, parsers only read the input files to fill the internal structures, while the state change later during planning-time.

If your method is ever decomposed and its preconditions satisfied by the current state, the subtasks with free variables ground at this point replace the current task and the decomposition process continues.
If a subtask fails the planner backtracks and tries other unifications and methods to solve that task, undoing previous state changes.
This is easy to see in the Basic HDDL example where someone wants to trade a banjo for a kiwi or vice versa.
The swap task tries the have_first method, it fails, and without free variables to be unified differently it tries have_second.
If a sequence of subtasks (which you called chain) was not possible this instance would have zero or two have predicates at the final state, but it is working as expected so the problem is elsewhere.

The variable ?hero remains free in your example, it should either be propagated through :task variables or unified by :preconditions.
This is probably the reason it fails, you can check for common mistakes with the Wise extension: ruby Hype.rb <domain> <problem> wise run.
It should display something like this: method goto test_method never declared variable ?hero from (action_1 ?hero ?from ?to).

from hypertension.

Considering there was no feedback I will close this issue in a few days if nothing happens.

from hypertension.