Good afternoon,
I hope you are all doing well.
I might be digging up an old topic, but I have the exact same problem with UE 4.26+.
In my test I spwan three BP_cableActor with a Blueprint script (StartScript_BP) who’s giving me some debug log.
In my test, the cables width variables values seem to be correctly set for each cable (cf debug).
Both with the inner SET operation or the outside SET operation as well (for cable 1).
Strangely the mesh don’t seems to be updated, even if the value is correctly set.
If I manually change the value while being in simulation (who is useless as the value is set correctly with the script) the rendering is then updated.
This is very strange because this mean we cannot procedurally generate cable with specific width value. Do you know a work around (maybe to force the rendering pass), or at least a hack before this issue is solved ?
@TJ V 
STAFF any idea ?
I’m sharing my basic test code in the next comment.
Sincerely
Kosen