Git push: fatal: Out of memory, malloc failed

Dear all,

I’m working with gitlab 9.5.2 and want to push data to my repository. Every time I got the following error:
fatal: Out of memory, malloc failed (tried to allocate 268435456 bytes)
fatal: The remote end hung up unexpectedly

I still checked this error message and changed settings as written here:

But this does not resolve my problem, still got this error. Put all mentioned settings up to 2g.

When I reboot my Unix machine, I can push without any error.
Do you have any idea?

Would be nice to get some help!

Thank you and best!