The UI to configure the LDAP Connection Pool is implemented wrong. The LDAP Connection Pooling Configuration is a server wide global configuration, not per individual LDAP provider. Currently, the settings are duplicated and applied with every single LDAP provider, which causes race conditions. Further more, changing any of the settings require a server restart to become effective.
The impact of this issue are race conditions when there is more than one LDAP provider configured. This will cause severe performance issues because the connection pool is not configured as expected, which are hard to debug and analyse.
See also the discussion on keycloak-dev.
Suggested solution is to remove the LDAP Connection Pool Preferences from the UI and replace them with wildfly subsystem configuration or system properties.
Another possibility would be to introduce a global settings menu in the admin-ui.