Complex profiles: wall vs. beam junctions - bug?

[Anonymous]

Having just migrated a v11 project file to v12 to take advantage of some of the new features, i've noticed some inconsistent behavior regarding complex profiles when using the core only function in terms of the way walls and beams clean up at junctions (haven't tried other element behaviour yet).

I did consider it may have been other elements in the file causing the problem (solid object operators, beam/layer priorities etc) so i selected an area well away from project model and tried to repeat the result.

I've traced the same outline using the beam and wall tools, applying the same complex profile to each. Result: both appear fine with 'entire structure' selected but with either 'core only' or 'without finishes' selected, only the wall corners mitre correctly; the beams appear incorrectly as in the attached image (walls below, beams above). I thought it may relate to beam offset setting and finish layer thickness but i can't seem to see a connection despite varying the beam offset figure to try and get them to mitre correctly (but then there is the issue that it would be incorrect in plan).

Any insight into this behavior would be appreciated.