Most of time, "Network access: Do not allow storage of passwords and credentials for network authentication" is used to disable "sessions" Cached credentials (ability for the user to connect to the machine when no Domain Controller is available) but has a side effect: You cannot store the account's password in scheduled tasks. The problem is that this setting disables "sessions" cached credentials but also the Credential Manager (which is used among other things to store passwords in scheduled tasks).
Disabling this setting is often in contradiction with the company's security policy.
A workaround is to not use "Network access: Do not allow storage of passwords and credentials for network authentication" but use instead "Interactive logon: number of previous logons to cache (in case domain controller is not available)" and set the number of cached logons to 0. With this setting, you'll be able to save credentials in your scheduled tasks (Credential Manager is enabled) but the "sessions" cached credentials will be disabled.
Microsoft