Bug with outputs

[tbaptistal]

Describe the bug
unit_invested isn't showing the real value.
units_on is having abnormal spikes, which are not visible directly in the production of heat.

As shown below, we see that the model truly invested in this new good heater on 01-01-2026.

To Reproduce
2 units producing heat from gas. One is bad but already in place (low efficiency), and the other is good with high efficiencies but needs to be invested in.
Simulation is daily from 01-01-2025 to 01-01-2030.
Investment is only starting on the 01-01-2026 and is occurring yearly.

Expected behavior
I expected the value to be 1 on 01-01-2026 in unit_invested as a new unit is generated.
I don't expect to have these spikes in the units_on output.

Desktop
SpineOpt: 0.9.2
Toolbox: 0.10.0.dev12
Windows 11
unit_invested_example.json

unit_invested_example_output.json