19c shared memory segments changes with AMM on Solaris

For those of you who are on Solaris - did you notice that 19c changed the way it allocates os shared memory segments when using AMM (MEMORY_TARGET) ? When checking with "pmap -xs" I am finding that it is not creating OSM (Optimized Shared Memory) segments.
This was not happening in 12.1 and 12.2. Instead it creates numerous non-locked allocations in regular shared memory segments.
Not OSM, not ISM and not DISM. Just regular shmid. Which of course makes them pageable and swappable and not a good thing. Even pmap -x runs noticeably slower.

I also noticed that USE_LARGE_MEMORY value flips to False with AMM. This also was not happening in 12.1 and 12.2.

According to the doc *"This parameter is applicable only on the Linux operating system. However, setting this parameter to FALSE can cause performance degradation on any platform"* Which makes me wonder - why does 19c flip it to false with AMM if it causes degradation ?

I have SR where support confirmed that USE_LARGE_MEMORY flipping to false with AMM started in 19c.
In SR they also stated that I should NOT try to set it back to true wen doing AMM (which I tested succeeds in making AMM use OSM segments again )

Anybody knows of another way to make 19c use OSM Solaris segments with AMM ?