I can reproduce this on my Linux desktop with all the IT, S3M, PSM, and MOD files - basically all the tracker formats. I'm not sure what GZDoom changed to break these - I'm guessing it's not intentional, because tons of mods use tracker music and they are probably now also broken. I'll see what I can find out, thanks for the bug report.
Which OS are you running GZDoom 4.14.0 from?