Riding through Daggerfall's east gate always ends up with the character being forcibly dismounted just outside the city limits. It showed up with Stonethorn (although it may be a very old bug that's resurfaced).
PC, both servers, both directions.
PC NA, PC EU
"Instead of taking the best of the dolmens (predictable rotation), the best of the geysers (scalability based on number of players), and the best of the dragons (map location and health indicators) and adding them together to make a fun and dynamic world event scenario, they gave us....... harrowstorms."
https://forums.elderscrollsonline.com/en/discussion/comment/6850523/#Comment_6850523