[REGRESSION] Multiple maven instances working on same source tree can lock each other

I have a large multi modules java maven build where:

• phase 1 - basic build + unit tests + jacoco - 40 min
• phase 2 - sonar:sonar 20 min
• phase 3 - final packaging and basic smoke-test - 20 min

To take advantage of Maven multi-threaded build, during the reactor build, one of our maven module spins another instance of Maven to run sonar:sonar goal right after the basic build is done.

This means our phase 2 and phase 3 run in parallel sharing the same source tree, same local maven repo (where sonar:sonar should have all needed dependencies at the share local maven repo to run its task)

With maven-3.8.5, parallelization is no longer possible, phase 3 is blocked until phase 2 is done.

I am able to trace it to https://github.com/apache/maven/pull/628 where the locking started the happen

How does the lock mechanic work? there must be a local file where both Maven instances are watching each other. Is there an option to disable this lock?