The latest beta update (iodéOS 7.6) should have resolved the signing issue and installed the latest version of Breezy Weather (6.2.0). From then on, you can install newer versions again via the Breezy Weather F-Droid repo, the iodéOS Apps F-Droid repo, the IzzyOnDroid F-Droid repo or the standard flavour from GitHub. For me, the order of the F-Droid package sources is as follows:
I have Breezy Weather directly from its repo (, then two repos for quick updates from SchildiChat, then my OEM’s repo), iodéOS apps (, then two repositories from another custom OS (which has a few cool apps that I use)), then the microG Project, then the Guardian Project, then IzzyOnDroid, and then F-Droid, because F-Droid usually offers different flavours of apps.