[keycloak-user] Operation ("add") failed - address...

[K K]

I have migrated configuration from keycloak-server.json file to standalone.xml and since that for some reason Keycloak is failing to start:

https://pastebin.com/KkcC1hL7

If I remove Mongo configuration from standalone.xml and put it back again to keycloak-server.json it is working back again.

standalone.xml: https://pastebin.com/VTErGeGb
keycloak-server.json: https://pastebin.com/CX87EYA5

I tried to replace migration strategy from update to manual or remove it completely but it seems that is not the problem.
any idea why?