Cannot ping core and UE after Tunneling

[ns-rh21]

Hi, I ran my 5gcore and cu on a remote server. and du and UE in my pc. the UE received ip from 5gcore. but i cannot ping from UE the core and vice versa.
for example no answer in ue side for this :
sudo ip netns exec ue2 ping -I tun_srsue 10.45.0.1

WHY?
******************************************* UE*****************************
sudo srsue --rf.device_name=zmq --rf.device_args="fail_on_disconnect=true,id=ue2,base_srate=23.04e6,tx_port0=tcp://127.0.0.1:2005,rx_port0=tcp://127.0.0.1:2004" --gw.netns=ue2 ue_zmq2.conf
Active RF plugins: libsrsran_rf_uhd.so libsrsran_rf_zmq.so
Inactive RF plugins:
Reading configuration file ue_zmq2.conf...

Built in Release mode using commit ec29b0c1f on branch master.

Opening 1 channels in RF device=zmq with args=fail_on_disconnect=true,id=ue2,base_srate=23.04e6,tx_port0=tcp://127.0.0.1:2005,rx_port0=tcp://127.0.0.1:2004
Supported RF device list: UHD zmq file
CHx base_srate=23.04e6
CHx id=ue2
Current sample rate is 1.92 MHz with a base rate of 23.04 MHz (x12 decimation)
CH0 rx_port=tcp://127.0.0.1:2004
CH0 tx_port=tcp://127.0.0.1:2005
CH0 fail_on_disconnect=true
Current sample rate is 23.04 MHz with a base rate of 23.04 MHz (x1 decimation)
Current sample rate is 23.04 MHz with a base rate of 23.04 MHz (x1 decimation)
Waiting PHY to initialize ... done!
Attaching UE...
Random Access Transmission: prach_occasion=0, preamble_index=0, ra-rnti=0x39, tti=334
Random Access Complete. c-rnti=0x4601, ta=0
RRC Connected
PDU Session Establishment successful. IP: 10.45.0.9
RRC NR reconfiguration successful.

---

sudo ip netns exec ue2 ip a show tun_srsue
9: tun_srsue: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN group default qlen 500
link/none
inet 10.45.0.9/24 scope global tun_srsue
valid_lft forever preferred_lft forever

---

sudo ip netns exec ue2 route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 10.45.0.1 0.0.0.0 UG 0 0 0 tun_srsue
10.45.0.0 0.0.0.0 255.255.255.0 U 0 0 0 tun_srsue

********************* core side*****************************
ip a
ogstun: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1400 qdisc fq_codel state UP group default qlen 500
link/none
inet 10.45.0.1/16 scope global ogstun
valid_lft forever preferred_lft forever
inet6 2001:db8:cafe::1/48 scope global
valid_lft forever preferred_lft forever
inet6 fe80::245:12d3:c8e9:7203/64 scope link stable-privacy
valid_lft forever preferred_lft forever

---

route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 146.48.80.1 0.0.0.0 UG 0 0 0 enp226s0
10.45.0.0 0.0.0.0 255.255.0.0 U 0 0 0 ogstun

---

sudo iptables -t nat -L -v
244 14640 MASQUERADE all -- any ogstun 10.45.0.0/24 anywhere

Ip forwarding is enabled in both sides.