To help around this bug one can do the following:

(a) if you change the Control Variable setting back to Temperature, the setpoint manager symbol re-appears. , If the visual handle for deleting the SPM is still missing, switch between the displays of HVAC loops and return to the original loop: now also the handle for deleting the SPM becomes visible, and you can delete are able to delete the setpoint manager, SPM, if necessary.

(b) if you reset switch between the displays of HVAC loops Control Variable and return to Maximum Temperature (or other options), the setpoint manager symbol loop with the missing SPM symbol, will again disappear, but at least the visual handle for deleting SPM may still remain the setpoint manager becomes visible.

In this way it is possible to do HVAC loop editing despite the bug.