I see what you mean. My j5 is broken, i can't do any testing, but i have an idea on why.
Android 11 brought in new encryption/decryption protocol. Roms were building fine, as was aosp based recovery. Twrp and ofox builds were viewing things as encrypted (file names all jumbled up).
The fix was merged on or about december 16, when the twrp source code was 3.4.0 (later updated to 3.5.0 on dec 28).
Jens's twrp build is 3.3.1, and built on feb 15, 2020, while mine is 3.5.0, and built after the encryption fix was merged.