This notice appears for feeds with just the `Continuous Stops` feature, which isn't a GTFS-Flex service even though it's in the Flexible Services group. We should modify it to display for every feature in the Flexible Services group except `Continuous Stops`.
Originally posted by @emmambd in https://github.com/MobilityData/gtfs-validator/issues/1861#issuecomment-2463149927