Resolved! The Build Analyzer says my processor STM32L443CC has 64K RAM and 16K RAM2. And I am not using any RAM2. What is RAM2 and how do I use it?
On other processors sometimes there are keywords when defining variables to specify which memory area the variable should be stored in. Or there is a #pragma statement. I have not seen either in the STM32 or the IDE. I am guessing RAM2 might be a goo...