Jon Fleming - 2020-05-30

I'm trying to create some single files from individual files that were
captured before a discussion forum went down. The topics I'm interested
in have hundreds of individual files to be merged into one.  I've
uploaded a zipped example to
https://mega.nz/file/z0hy3KxL#MbUvjDa-C7VWv_SGGARik0GMgrTCFoF0ovFr6gis5dY.

If I merge 10 or 100 of these files, all is well.  But if I merge all
251, files 9216-002.html through 9216-005.html are not placed in the
proper order but are scattered throughout the file.  This happens for
every set of files I try, but different files are misplaced always
starting with file 2.

Bug?