[BUG] Ignore signature verification doesn't work

If you go to settings, scroll almost on the very bottom and toggle "Ignore signature verification" won't work.
If you try to install / update the same app from other source / repo it won't install.
I've just tried update Shelter initially installed from F-droid to Shelter from dev repo - it didn't work, app wasn't updated.
That happened many times before to another apps, when tried to update apps present on IzzyOnDroid but not present yet in F-droid, which is known about "delays" in publishing made due to app verification.

Any fix for that?

Here the info from the app Notifications Recovery.