Astlinux is designed to write to its storage as little as possible, in order to lengthen the lifespan of its hardware. When you first install Astlinux, the whole system is read-only. You need to configure persistent storage options.
Even if you set your timezone correctly on the Network tab, and the time appears to be correct elsewhere in the system, records listed on the CDR tab might have GMT timestamps. This is nothing to do with Astlinux, but is an Asterisk setting. Use the Edit tab to open cdr.conf, and look for the following line:
usegmtime=yes ; log date/time in GMT. Default is “no”
Change this value to “no” to have the system timezone used for the CDR.
If you are running Astlinux 0.7.1 or later, Asterisk sounds packages are not installed by default. If a call tries to play a missing sound file, the call is silently terminated. To install the necessary sounds packages, see Sounds Packages.