Enter edit mode even though the block instance is not being edited

Even though I haven’t edited the block instance, the color of some blocks changed like when I was editing, and I couldn’t edit.
I solved it by inserting blocks or importing the whole file into a new file.
In addition, there are some display bugs such as the color suddenly turns black while editing the material, and the original material is displayed after a while.
My PC is a laptop computer, but the following two GPUs are used. Is this a GPU issue?

intel ® HD Graphics 630
NVIDIA GeForce GTX1050 Ti

Hello - try using the Unlock command - does that sort it out? Can you repeat the problem?

-Pascal

All layers are visible and not locked. So it became like a question. Even if I insert a block, I can edit the newly inserted block, but the same existing block remains frozen and cannot be edited. I think it’s a bug.
Therefore, I solved it by importing the original file by creating a new file. I would like to know the cause of this problem.

Hello - my suggestion was to use the Unlock command - this does nor affect layers. BlockEdit locks objects that are not being edited and unlocks them when the edit is done - this failed for reasons I do not know.
-Pascal

The same phenomenon happened again, and when I typed unlock, it worked fine.
Thank you very much. It was helpful.

Hello - can you make that happen reliably? What are the steps to get into that state?

-Pascal

This happens when you edit a block instance repeatedly. While editing a block instance, a window called block edit appears, but it seems that there are times when editing is not canceled even if the window disappears when you press OK.

I am creating an apartment building, and each floor is a block instance. Since it is made that there are more blocks in that block, block editing work will occur many times. Although it is about 50MB, the movement of Rhinoceros gradually slows down, and this phenomenon occurs.

Hello - I’ll try to reproduce this. (meantime, it occurs to me it might not be bad to use Worksession for your individual floors, rather than huge complicated blocks)

-Pascal

Does a work session mean creating a file for each floor? Is it wrong to create more block instances inside a block instance?