Service vehicles from addons will permanently disappear if a service building with addons that increase total service vehicles is destroyed and then another service building is created to replace it.

When trying to upgrade this new service building with vehicle increasing addons all of the addons will appear empty and no vehicles will be produced from them.

This effect is permanent.

Only by increasing the number of addons above the limit of the destroyed original service building will you be able to start producing more vehicles per upgrade, however the upgrades before this will never have any vehicles.

Steps:

1. Create a clinic and apply two additional ambulance addons.

2. Destroy this clinic.

3. Build a new clinic and apply three additional ambulance addons.

4. You now have a clinic with two ambulances instead of four.

Additional Information:

1. This reproduces with all service vehicles on all service buildings.

2. The clinic is just an example.

3. Deleting this second service building will only make the situation worse as it will reproduce the bug with the new number of addons.

4. If a service building is destroyed through a disaster this issue also reproduces.

The following still reproduces the issue:

Turning off the power and deleting the building.

Waiting for the vehicles to return home before deleting the building.

Turning off the power and deleting each module individually before deleting the building.

Edit: Added more information