How to configure Stateful-NAT in IP SLA

[ps12]

I am trying to configure Stateful-NAT in my IP SLA environment. The NAT configuration of router 1 is below. The same configuration is reflected on router 3 which is the backup NAT router. However, the SNAT doesn't show any peers and no translations.

sh ip nat stat
Total active translations: 0 (0 static, 0 dynamic; 0 extended)
Outside interfaces:
  FastEthernet2/0, FastEthernet3/0
Inside interfaces:
  FastEthernet0/1
Hits: 0  Misses: 0
CEF Translated packets: 0, CEF Punted packets: 0
Expired translations: 0
Dynamic mappings:
-- Inside Source
[Id: 1] access-list THANOS_STARLORD_NAT pool THANOS_STARLORD_NAT refcount 0
Appl doors: 0
Normal doors: 0
Queued Packets: 0

conf t
ip access-list standard THANOS_STARLORD_NAT
permit 188.115.126.192 0.0.0.63 
exit
ip nat pool THANOS_SLORD_NAT 59.99.99.57 59.99.99.57 prefix-length 30
ip nat inside source list THANOS_STARLORD_NAT pool THANOS_STARLORD_NAT mapping-id 1 overload
exit
ip nat stateful id 1     
primary 172.16.15.50
peer 172.16.15.62
mapping-id 1  
end
wr

[paul driver]

Hello

Are you running HRSP?
Does each side of the snat have a unique snat ID but the same mapping id ?.

Sh ip nat snat distributed