Hi ADB100,
Thank you for taking the time to help me.
I have cut some lines from the configuration without (hope it is enough else let me know and yes the local net of the remote site 2 site vpn is 150.150.99.0

:
interface Ethernet0/0
nameif inside
security-level 100
ip address 10.10.20.13 255.255.255.0 standby 10.10.20.14
!
interface Ethernet0/0.31
vlan 31
nameif test-net
security-level 20
ip address 10.10.31.1 255.255.255.0 standby 10.10.31.2
!
access-list no-nat extended permit ip 10.10.0.0 255.255.0.0 150.150.99.0 255.255.255.0
access-list outside_cryptomap_4 extended permit ip 10.10.0.0 255.255.0.0 150.150.99.0 255.255.255.0
global (outside) 10 interface
global (outside) 4 10.10.20.254 netmask 255.255.255.255
global (dmz) 10 interface
nat (inside) 0 access-list no-nat
nat (inside) 4 access-list 101010nat
nat (inside) 10 10.10.10.0 255.255.255.0
nat (inside) 10 10.10.20.0 255.255.255.0
nat (test-net) 10 10.10.31.0 255.255.255.0
nat (outside) 4 access-list outside_nat_outbound
static (outside,inside) 10.99.103.0 150.150.99.0 netmask 255.255.255.0
static (outside,outside) 10.99.103.0 150.150.99.0 netmask 255.255.255.0
static (inside,test-net) 10.10.20.53 10.10.20.53 netmask 255.255.255.255
static (inside,test-net) 10.10.20.50 10.10.20.50 netmask 255.255.255.255
static (test-net,outside) 10.10.31.31 10.10.31.31 netmask 255.255.255.255
static (test-net,inside) 10.99.103.0 150.150.99.0 netmask 255.255.255.0
access-group inside_access_in in interface inside
access-group test-net_in in interface test-net
access-group acl_out in interface outside
crypto map XXXMap 2 match address outside_cryptomap_4
crypto map XXXMap 2 set peer test-WG
crypto map XXXMap 2 set transform-set ESP-3DES-SHA