Server doesn't play whole folder

I have a strange problem: there is a folder includes 901 MP3 files on my server, and it shows correct number of files under "Music folder", but when I press "Play all" it selects first 500 files only. I can play any of files directly, but "Play all" is a different story: 500 file only and that's all. It seems some kind of strange limitation of 500 files exactly, because when I select any other folder with smaller number of files, I haven't any problem with it.

My server is LMS 7.9.2 on Raspberry 4; OS type is Arch Linux Arm 64-bit
My player is Squeezelite 1.9.6 on Raspberry Pi 3; OS type is Arch Linux Arm 32-bit
Access is from Win7 64 through web interface; browser is IE11