It was initially happening from all mirrors that I could tell but only on updates, for both F27 and F28, modular would work but updates x86_64 would fail it appears to have fixed itself around 12pm EDT yesterday.

On Tue, Jul 24, 2018, 2:50 AM Adrian Reber <adrian@lisas.de> wrote:
On Mon, Jul 23, 2018 at 11:17:17AM -0400, Paul Andrel wrote:
> Getting an interesting set of errors trying to check for updates today on
> F28.
>
> Cannot download '
> https://mirrors.fedoraproject.org/metalink?repo=updates-released-f28&arch=x86_64':
> Yum repo downloading error: Downloading error(s):
> repodata/c74e64d676764568df8ba0215133832e9e7ea75035e8ba6c1e6b867e8b7ca489-primary.xml.gz
> - Cannot download, all mirrors w
> ere already tried without success;
> repodata/516a5ec60578a1356d2e76080f2dc1bda6d641e5f6ed8cf65bbeb4c8ce664e76-filelists.xml.gz
> - Cannot download, all mirrors were already tried without success;
> repodata/9ad807c3fd6664b904a4bb1dafc6b4460ab01847f2d218dbee8bb1fa454bd08a-pres
> todelta.xml.gz - Cannot download, all mirrors were already tried without
> success;
> repodata/912daaac74659e0912e835f74f8a0de347bdab38ebeb8f50e61a8a9a32b67387-updateinfo.xml.xz
> - Cannot download, all mirrors were already tried without success.
> Error: Failed to synchronize cache for repo 'updates'
>
> Looking at my mirror it apparently doesn't seem to have these repodata
> files, I have quite a few but none like these, any recent changes?

Hmm, so I have not seen any other error reports and right now everything
seems to work for me. Do you see this for only one mirror or for all
mirrors?

                Adrian