Dial returns exited non-zero on when hangup on pstn side E1

I?m rephrasing my previous post, given my new findings.

I get a call from pstn via an E1, then dial into a Voip extension.

If the extension hangs up, the next line of the dial gets executed,

If the zap - E1 side hangs up, the next line doesn?t, dial returns exited non-zero.