When a glowfic post contains tildes (e.g. https://glowfic.com/replies/1750327#reply-1750327), they come through raw in the glownotify update message, potentially being interpreted as markdown for strikethrough. Tildes and other markdown-relevant characters should be escaped to prevent this sort of thing.
!glownotifycommand sometimes yields an informative error/documentation message, but not in all cases; on at least one occasion it produced a different, less informative error message. I haven't figured out exactly what the criteria are. Places where it would be nice to produce it include:
!glownotifyin a channel with insufficient permissions (additional error-message information here would be helpful)
For reference, the message:
!glownotify: Manage subscriptions for glowfic post Minimum Arguments (2): [subscribe|unsubscribe] [URL of post|Author name]
("swag" is underlined; I don't know of a way to produce that in sourcehut markdown.)