Can you add a trace options file to both VR and review the results of the failed peering.
set routing-instances VR1 protocols bgp traceoptions file bgpVR1
set routing-instances VR1 protocols bgp traceoptions file size 10k
set routing-instances VR1 protocols bgp traceoptions file flag update detail
set routing-instances VR2 protocols bgp traceoptions file bgpVR1
set routing-instances VR2 protocols bgp traceoptions file size 10k
set routing-instances VR2 protocols bgp traceoptions file flag update detail
show log bgpVR1
show log bgpVR2