Bug Failing tests because of unity message: Unhandled log message: '[Assert] TLS Allocator ALLOC_TEMP_TH

Hello,

I'm randomly having the following problem:
When I run an async test, of this kind

Code (CSharp):

1.        
2. [Test]
3. public async Task DummyAsyncTest()
4. {
5. //Arrange
6. //Act
7. //Assert
8. }
9.  

I am having a failing test because of this Unity error message:
Unhandled log message: '[Assert] TLS Allocator ALLOC_TEMP_THREAD, underlying allocator ALLOC_TEMP_THREAD has unfreed allocations, size 192'. Use UnityEngine.TestTools.LogAssert.Expect

This error appears sometimes when I run it on Unity Editor, but it's much more common from command line in a pipeline.

I can't figure out neither which is the problem nor a pattern to submit a bug.

My guessing is that the UTF is allocating some structure for launching the async test, and somehow it's not freed

Any ideas?

Further information:
Test framework: 2.0.1-pre.18
Unity 2020.3.40
The tests are in Editor mode

Thank you