Can you try adding this snippet to your setup()
code and check whether my workaround really works?
void dummy(const char* filter, const char* data) {
}
void setup() {
// all your usual stuff
...
if (someConditionToOnlyDoWhenNeeded == true) {
// this is just to add mutating data into the hash
Particle.subscribe(String(Time.now()), dummy, MY_DEVICES); // <-- correction from previously PRIVATE
}
}