The issue appears to be when the VLAN 10 should be mapped to VLAN 210, actually this is not happening on the LSW4 switch.
Config LSW4:
!Software Version V200R011C10SPC600
#
vlan batch 10 2010
#
traffic classifier test operator and
if-match vlan-id 10
#
traffic behavior remark
#
interface GigabitEthernet0/0/2
port link-type trunk
port trunk allow-pass vlan 2010
#
interface GigabitEthernet0/0/3
port link-type hybrid
qinq vlan-translation enable
undo port hybrid vlan 1
port hybrid tagged vlan 10
port hybrid untagged vlan 2010
port vlan-stacking vlan 210 stack-vlan 2010
port vlan-mapping vlan 10 map-vlan 210
#
Config LSW3:
!Software Version V200R011C10SPC600
#
vlan batch 2010
#
interface GigabitEthernet0/0/1
port link-type dot1q-tunnel
port default vlan 2010
#
interface GigabitEthernet0/0/2
port link-type trunk
port trunk allow-pass vlan 2010
#

We have issues a ping from 192.168.2.1 towards 192.168.2.2 and vice versa then we captured packets between switches. In both cases we noticed the ARP being broadcasted without a response. Below is the capture
SW5 to SW4:

SW4 to SW5:
SW3 to SW4:
SW4 to SW3:

During the tests it has been confirmed that we can’t enable both VLAN mapping and VLAN stacking functions in the same interface.
Starting with version V200R011C10SPC600, there is a new command available that can do both operations in the same command.

Starting with V200R011C10SPC600 we can enable both VLAN mapping and VLAN stacking functions using the same interface and command.
On LSW4 interface Gi 0/0/3 we configure as follows:
#
interface GigabitEthernet0/0/3
port link-type hybrid
qinq vlan-translation enable
undo port hybrid vlan 1
port hybrid tagged vlan 10
port hybrid untagged vlan 2010
port vlan-stacking vlan 10 stack-vlan 2010 map-vlan 210
#