Chosen Solution
I upgraded to ios 12.1.4 and still restart itself from 2-3 minutes interval I have a log with errors from Apple Configurator , if anyone could help, it will be grateful! I have the log file, I could send it to e-mail. Thank you!
You could try to downgrade your iOS to the previous version (12.1.3) if Apple is still signing it (according to this website - yes!). Just follow the instructions on this website.
