DHCP Relay on EX4600 not working when DHCP server is not routed in EX4600 device

Hello all!

I have a problem when trying to migrate DHCP server. We're moving our DHCP server to a new datacenter from our office, when doing this we noticed that our EX4600-40F which acts as router for our office wont forward dhcp relay requests to the new DHCP server at all.

And when adding traceoptions it wont log any failures either.
Our office DHCP server has IP: 192.168.98.5 (irb.98)

Our new DHCP server in DC has IP: 10.101.0.6

Client network at office: 192.168.100.0/23 (irb.100)

Config at the office (working configuration):

markus@core-sw01# run show configuration forwarding-options dhcp-relay
forward-snooped-clients all-interfaces;
overrides {
    allow-snooped-clients;
    layer2-unicast-replies;
    trust-option-82;
}
relay-option-82;
server-group {
    DHCP-SERVERS {
        192.168.98.5;
    }
}
active-server-group DHCP-SERVERS;
group DHCP-RELAY {
    interface irb.100;
}

markus@core-sw01# run show route 10.101.0.0

inet.0: 165 destinations, 172 routes (165 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

10.101.0.0/23      *[BGP/170] 6w2d 13:52:44, localpref 100
                      AS path: 64512 I, validation-state: unverified
                    > to 10.100.0.16 via irb.3051

markus@core-sw01# run show configuration interfaces lo0
unit 0 {
    family inet {
        address 10.100.0.7/32;
    }
    family inet6 {
        address 2a0e:bb80:1001::1/128;
    }
}

Ping from core-sw01 (EX4600-40F) to DC DHCP-server:

markus@core-sw01# run ping 10.101.0.6 source 192.168.100.1
PING 10.101.0.6 (10.101.0.6): 56 data bytes
64 bytes from 10.101.0.6: icmp_seq=0 ttl=63 time=0.648 ms
64 bytes from 10.101.0.6: icmp_seq=1 ttl=63 time=11.355 ms
^C
--- 10.101.0.6 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.648/6.002/11.355/5.354 ms

markus@core-sw01# run ping 10.101.0.6 source 192.168.98.1
PING 10.101.0.6 (10.101.0.6): 56 data bytes
64 bytes from 10.101.0.6: icmp_seq=0 ttl=63 time=0.702 ms
^C
--- 10.101.0.6 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.702/0.702/0.702/0.000 m

Relay works fine within the switch even when it's done over l3-interfaces (server on irb.98 and clients on irb.100). Relay does not work when DHCP-server is not routed in switch.

Any clues on why it's like this?