Why are old blueprint instances not updated when i modify the parent blueprint?

Hello,

I made a blueprint, then put many instances of that BP in my level, then strongly modified the BP.

The new instances behave correctly, but the old ones do not.

Here are two instances with exactly the same parameters (exposed variables for rectangle width, height and z position, same for the light):

9311-bp_update.jpg

The one on the left is a newly created and behaves correctly (its base stands correctly on the floor and the light is up in the air), while the one on the right (with exactly the same parameters) is wrong (large size, and both rectangle and light have 0 z value).

Some things still work in the old ones, for instance, the aspect ratio is set correctly (but not the scale), but some properties seem to be frozen or corrupted.

They are supposed to be identical, except one was created before the strong modifications, and the other after them.

I have like 30 instances of ancient version and i would not want to recreate them one by one.

Is there a way to reinitialise the BP behavior (maybe empty some cache directory or something ?) so that all the BP instances behave correctly ?

i have tried to stop/restart several times, the corrupted ones remain corrupted.

Thanks

Cedric