1) The error could be due to early cleanup or purge of the log file before the restore could have processed. Increase the time duration for retaining the backups files

2) no idea about this.

3)Network hiccup: Occasional hiccup which led to the network being inaccessible. Whenever this happens, make sure that the subsequent schedule of the entire process was successful. If it was, no need to worry but do open a request with Infrastructure guys to let them know about the network issue.

Chandan