[keycloak-user] Error linking users between realm

[triton oidc]

Hi,

in my current scenario, i have an error in linking user between two
Keycloak IDP
i got two servers in 4.8.3.Final
both in debug mode
./jboss-cli.sh --connect
--command='/subsystem=logging/root-logger=ROOT:change-root-log-level(level=DEBUG)'
./jboss-cli.sh --connect
--command='/subsystem=logging/logger=org.keycloak:write-attribute(name=level,value=DEBUG)'

When i try to link a user, i get an error
"An internal server error has occurred"
after login on the second IDP

In the log i see a :
 WARN  [org.keycloak.events] (default task-3) type=LOGIN_ERROR,
realmId=RedAirlines, clientId=null, userId=null, ipAddress=172.18.56.212,
error=invalid_code

Nothing in the log for the second IDP

If i reload the webpage, i see the user is linked.
However when i try an exchange token scenario, i got a
"Not present cache item for key LoginFailureKey [ realmId=RedAirlines.
userId=XXX" error
which i'm pretty sure is related to the linking issue (because the token
exchange scenario works, when i login my user using "another realm
authentication")

I can paste some more details if it can help,
Thanks for any clue

Amaury