Asterisk 13 / moved from 1.14 / realtime queues problem / first caller answered last

Hi all

Last Saturday I changed our main platform from 1.14 to version 13 (long overdue!). We use realtime queues with very basic “ringall” strategy, no priorities.

We have around 70 doctors’ clinics and a typical installation uses a small proprietory program for each user that displays calls that are waiting in queue for each individual user (agent). Since Monday, several of our customers have noticed that the first caller in the queue gets “left behind”, i.e. is the last to ring through. I’ve witnessed this happening directly from “queue show …” where two calls were waiting, and call no. 2 was definitely answered before call no. 1.

Example from “show queue qxxx”

qxxx has 2 calls (max unlimited) in ‘ringall’ strategy (56s holdtime, 130s talktime), W:1000688, C:160, A:23, SL:0.0% within 0s
axxx (ringinuse enabled) (realtime) (in call) (Ring+Inuse) has taken 112 calls (last was 129 secs ago)
bxxx (ringinuse enabled) (realtime) (paused) (Not in use) has taken 5 calls (last was 10212 secs ago)
1. SIP/x.x.x.x-001d2c5f (wait: 1:10, prio: 0)
2. SIP/x.x.x.x-001d2fec (wait: 0:01, prio: 0)

There are two agents axxx and bxxx, but only axxx was taking calls at this time. In this case I witnessed call 2 being answered by axx before call 1.

Does anybody have an explanation for this strange behavior?