You can ask `wsl --status` which version is the default on your system. WSL1 is still in use on many systems from legacy installations, but also because it works inside VM systems that don't support double-virtualization, as with ARM Windows on Apple M1. One of many differences between the two is that WSL1 uses a POSIX gloss on NTFS as the filesystem, whereas WSL2 uses an actual Linux kernel with regular Linux filesystems. This naturally has a whole laundry list of implications for SQLite's locking and file I/O semantics.