I have followed the instructions at the link below to setup the following Win10 1909 feature pack updates...

Win10 Pro x86

Win10 Pro x64

Win10 Enterprise x86

Win10 Enterprise x64

I named the four ISO files as per the instructions in the link for the English files.

Three of the four are working fine...

Win10 Pro x86 1909 (107613-Win10_1909_enx32.iso)

Win10 Enterprise x86 1909 (107615-Win10_1909_en_enterprisex32.iso)

Win10 Enterprise x64 1909 (107611-Win10_1909_en_enterprisex64.iso)

However, with the Win10 Pro x64 1909 feature pack, Desktop Central keeps downloading the Chinese, French, and Spanish ISO files, which in turn hangs everything up for a long time due to having to download and replicate each of the additional three 4 GB ISO files, and using up valuable disk space (12 GB) on the Distribution servers.  I have replaced the ISO with a newly downloaded copy from the MS Business Center Downloads (Volume Licensing) site and started from scratch, and the same thing happened.  I have contacted DC support about this issue and was told this behavior is by design, with no explanation as to why only Pro x64 behaves this way, and not the other three.  I was then given a work-around of creating three dummy ISO files named 107609-Win10_1909_Spx64.iso, 107609-Win10_1909_csx64.iso, 107609-Win10_1909_Frx64.iso, to trick DC into thinking the ISO files were already there.  This work-around did not work, as DC proceeded to continue downloading the Chinese, French, and Spanish ISO files, and overwriting my dummy ISO files.  I have provided full server and DS logs and screen-shots to DC support, but wanted it to post here to see if anyone else has seen a similar issue.