Structure variable values reset when structure is modified

Hi !

I seem to have a serialization issue with USTRUCTs.
Every time i add/remove a variable (or just change the type of one), the value of all the variables on the structure are reset, everywhere in my project.

I thought this was the correct way of defining structures, but it seems to not be the case.

Question : how can I properly define a structure in code that doesnt break ?

Struct Example:

struct FInteractableConfig : public FTableRowBase


	FInteractableConfig() {
		HoldMethod = EHoldMethod::ClickOnce;
		SnapMethod = EGrabSnap::Free;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Config")
		EHoldMethod HoldMethod;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Config")
		EGrabSnap SnapMethod;


If I add a new variable to it (for example bool Whatever). Compile, close/reopen the project (unreal4 wont show me the modifications until then), then HoldMethod and SnapMethod would be reset to their default.
If I delete the newly added variable, the same happens.

I’ve had this issue for quite some while (4.17… ?) and skipped doing anything half serius with UE4 because of it. 1-2 years after, I come to think I may be doing something wrong in the definition of my structure.

Thanks !