Question for the repo managers,

Why do I sometimes see invalid checksums for drpm downloads?  E.g: This excerpt from the update this morning:

/var/cache/dnf/updates-7fc4c739b3909d9f/packages/selinux-policy-targeted-3.14.4-46.fc31_3.14.4-47.fc31.noarch.drpm: md5 mismatch of result
Some packages were not downloaded. Retrying.
selinux-policy-targeted-3.14.4-47.fc31.noarch.r  14 MB/s |  13 MB     00:00 

It almost always causes the total download size to be larger than any savings from using the drpm format:

Failed Delta RPMs increased 41.3 MB of updates to 43.3 MB (-4.1% wasted)

Is this a repo bug?