Serialization data mismatch

I added my custom Serialize() function to my USTRCT() to reduce its size for replication purposes. Problem is that now I experience serialization mismatch error. Length of serialized data(some variables) in the editor saved by default Serialize() function is different(obviously). Is there a way to drop specific editor save data or better yet, add serialization compatibility with old data?? I assume I’m not the first who encounter this issue yet I don’t find any tool to resolve it.

For anyone who stumble upon similar problem.
Eventually I used new(wrap) structure to envelop the old structure. So i have the old USTRUCT for UE4 serialization and my wrapper struct for custom serialization. Its not the most elegant solution but it works.