In Custom filters, if for one website, here wordreference.com, an unsupported filter is used, here wordreference.com###articleHead:has-text("exemple") (has-text() unsupported on Orion), then even valid filters, here www.wordreference.com###footer, will fail on this website.
Experience on www.wordreference.com/esfr:
In both
www.wordreference.com###articleHead:has-text("exemple")
www.wordreference.com###footer
and
www.wordreference.com###footer
www.wordreference.com###articleHead:has-text("exemple")
the #footer is not hidden.
But after removing the www. for the targeted website of one of the two rules,
www.wordreference.com###articleHead:has-text("exemple")
wordreference.com###footer
the #footer is now effectively hidden.
I don't know if that also occurs on desktop.
I expect unsupported filters to fail without affecting supported filters.
Orion 1.5.1 / iOS 27