PPSSPP 404 not found

https://flathub.org/apps/details/org.ppsspp.PPSSPP
If we click on install button, 404 not found error is shown

Whereas
flatpak install flathub org.ppsspp.PPSSPP works

I can download that file. Perhaps it was a temporary error?

We have been doing server maintenance at the time. It should be fixed since.