Weird duplicating block inside of block editor

This actually happens a lot and I’m completely clueless as to why/how.

I will be editing my block. I’ll hide, unhide things. Next thing I know I have a duplicate of the same block instance inside of my block. What I thought worked was to click on another block inside of the editor tree… and then back into the parent block. No, that is not working. I can never tell what to keep or what is really there or not. Most of the time (I think) I end up copying and deleting the strange duplicate block and closing. Once I close, the block completely disappears and UNDO will not rescue it. For the most part, I am normally lucky because I usually end up copying my block to edit it (mostly because this happens so much OR because I need to orient to whatever I need) — So when it does make this weird duplicate and I close… and it disappears – i have my other block still surviving… WITH the updated changes… go figure. Not sure what this is all about.

Hi,

Could you please read this description to someone near you. Who has never worked with your file and then ask him/her if s/he has understood the problem?

No pictures, no rhino opened, no file attached, just the same as here. Unclear description.

Thanks.

Does this happen in Rhino 5 or 6? Do you have objects inside the block in different layers?