So I tried again. First, I found out that I only have 95 thousand music files. The 110 thousand were data from my PC and included all the images that are in the music folder. So it seems that the application goes through all the files when scanning, but then does not create a database from them. I removed 20 thousand files from the folder for testing, but even these 75 thousand files did not lead to the creation of the database. So apparently there is a certain number of files that can be processed successfully, otherwise the database creation fails and it is probably not just a problem with the Android memory. I also tried it in the Foobar and Musicolet applications, there the database was created without any problems with the full number of files.
So you were right. While making various settings, I accidentally excluded a folder that was being scanned. Now everything is fine, I created a database with 96 thousand mp3 files without any problems. Now I just need to solve the problem of displaying images and Symfonium will be absolutely unbeatable.