The version numbers you provided correspond to a significant Forza Horizon 5 update released on October 10, 2023 , titled the Día de Muertos Update Highlights (Version 1.619.349.0)
Notable community-reported changes
Since those manifests were generated in late May to early June 2023, let us examine what legitimate Update Series 21 contained. This is the real content of the "mystery update." forza horizon 5 update 1619349 1624534 0
Despite the fixes, players immediately noticed a new problem: Texture pop-in on the Horizon Badlands. The game would sometimes render low-poly cacti for up to 5 seconds before sharpening. This set the stage for the next update.
Following closely in November 2023, this update launched the "American Automotive" series. The version numbers you provided correspond to a
While primarily a hotfix, this update sneakily added assets for the upcoming Horizon Creatives update:
Confirmed Patch Details (what to check)
While these specific builds were technical in nature, they bridged the gap into major content drops like Series 33: Apex Allstars, which introduced: