Git credential helper store flushes randomly

Hello.

I have very strange git credentials store behavior on one of my servers.
I Use Ubuntu 14.04 LTS and git  2.10.2. The server have multiple users with multiple projects, so they have got many different git credentials to different repositories.
I set git config --global credential.helper store, but the credential record strings from file ~/.git-credentials for one specific user disappears randomly. Especially for one specific repository.

I do not see any TTL for git credentials in credential.helper store on git documentation, so I can't even imagine, what could cause such strange behavior.

Is this a known problem and is there any solution to fix this problem?


Best regards,
Anton.