Query related to cleint open/not modifiable

Dear All,

I have the following doubts.

Suppose client 400 is not modifiable.

Now If I want change some object then I have to open the 400 client, so in SCC4, I will select the below option

"Changes w/o automatic recording, no transport allowed".

After that, some time, if I will try to change object immediately after opening client then it shows Clint is not modifiable.

After 1 minute or from other session of same client if tried then it allow to change.

What is the reason ?

Thanks in advance,

Nirav