How to teach Andoid how to properly use internal memory?

Question

Android

My smartphone has several gigs of internal memory divided into two parts for some reason. When I inserted the micro sd, I transferred everything I could to it. But still, part of the installation files, of course, remains on the internal memory. And here's the joke. For some reason, the phone consumes only the first part of the internal memory, ignoring its second part, says that there is no space. When I enter the settings, I see that 1.9 of the so-called "internal memory" is clogged and 4 gigs of "telephone memory" are completely unused. How to teach the phone to use these 4 gigs? (micro sd is also active and selected as the main file storage location)?

Answer 1

What is the apparatus? What firmware and version of android?