Problem was diagnosed to Spring monitoring Agent extension that is enabled by default in 10.5.x
To resolve the issue disable AspectTracing:
Change "TurnOn: AspectTracing" to "TurnOff: AspectTracing" in the AGENT_HOME/wily_10.5.x.x/extensions/SpringWS-f85e8b22-1.0.0/directives/toggles.pbd
Note: This trace is already disabled in 10.7.x Spring Extension.