Although the ufw was inactive at the time I ran tracking and source commands, I enabled the ufw and allowed ntp, but still see the reference id is zero.
$ sudo chronyc sources
210 Number of sources = 22
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
^? prod-ntp-5.ntp4.ps5.cano> 0 10 0 - +0ns[ +0ns] +/- 0ns
^? prod-ntp-4.ntp4.ps5.cano> 0 10 0 - +0ns[ +0ns] +/- 0ns
^?
alphyn.canonical.com 0 10 0 - +0ns[ +0ns] +/- 0ns
^?
pugot.canonical.com 0 10 0 - +0ns[ +0ns] +/- 0ns
^? prod-ntp-3.ntp4.ps5.cano> 0 10 0 - +0ns[ +0ns] +/- 0ns
^? prod-ntp-3.ntp1.ps5.cano> 0 6 0 - +0ns[ +0ns] +/- 0ns
^? prod-ntp-5.ntp1.ps5.cano> 0 6 0 - +0ns[ +0ns] +/- 0ns
^? prod-ntp-4.ntp4.ps5.cano> 0 6 0 - +0ns[ +0ns] +/- 0ns
^?
ntp2.belbone.be 0 10 0 - +0ns[ +0ns] +/- 0ns
^?
rumst.verbert.be 0 10 0 - +0ns[ +0ns] +/- 0ns
^? 45.87.78.35 0 10 0 - +0ns[ +0ns] +/- 0ns
^?
webserver.discosmash.com 0 10 0 - +0ns[ +0ns] +/- 0ns
^?
ntp1.unix-solutions.be 0 10 0 - +0ns[ +0ns] +/- 0ns
^? host-95-182-219-178.dyna> 0 10 0 - +0ns[ +0ns] +/- 0ns
^? ntp.ulyssis.student.kule> 0 10 0 - +0ns[ +0ns] +/- 0ns
^?
ntp2.unix-solutions.be 0 10 0 - +0ns[ +0ns] +/- 0ns
^?
ntp.devrandom.be 0 10 0 - +0ns[ +0ns] +/- 0ns
^?
ntp49.kashra-server.com 0 10 0 - +0ns[ +0ns] +/- 0ns
^?
radio-sunshine.org 0 10 0 - +0ns[ +0ns] +/- 0ns
^? 2a0e:f780:0:100::15 0 10 0 - +0ns[ +0ns] +/- 0ns
^?
time.cloudflare.com 0 10 0 - +0ns[ +0ns] +/- 0ns
^? 45.87.77.15 0 10 0 - +0ns[ +0ns] +/- 0ns
If that is all I can do on my system, then I have to ask the IT admin about the organization firewall.