Case 1:
1. Go to Housekeeping form
2. Reset it to default, save it.
3. Change settings:
Trigger data storage period => invalid value (5)
Services => unchecked
Audit=> unchecked
User sessions => unchecked
4. Try to save form, get error about invalid Trigger data storage period
Result: other settings changed to default, Services, Audit and User sessions became checked.

Case 2:
1. Uncheck Events and alerts
2. Set Services Data storage periodto invalid (1) and try to Save.
3. Error is present, but Events and alerts became checeked again.

Case 3:
1. Go to Housekeeping form
2. Reset it to default, save it.
3. Change settings:
Override item history period => checked
Data storage period => some custom value (945d)
Override item trend period => checked
Data storage periods => some custom value (945d)
4. Save form.
5. Press reset to defaults - Notice that all fields have changed to default values, also:
Override item history period => unchecked
Data storage period => 90d - disabled
Override item trend period => unchecked
Data storage periods => 365d - disabled
6. Press update.
7. Result: "Data storage period" values both remained custom, but not default.