You are incorrect and have been given the correct information. Weapons with anti-champion intrinsics have never been able to use champion mods. This has been the case since Eriana's Vow was introduced as the first anti-champion weapon back in Shadowkeep. For a more recent example of this, please refer to the archived Year 4 Known Issues [url=https://help.bungie.net/hc/en-us/articles/360054863011-Destiny-2-Year-4-Archived-Known-Issues-and-Vital-Information]article[/url], from before Arbalest received its update to be anti-barrier: [quote] Exotics The Arbalest Exotic linear fusion rifle will not work with anti-Champion mods in Season of the Lost. In a future update, anti-barrier will be added as an intrinsic perk for the weapon.[/quote] As shown, Arbalest was prevented from using anti-champion mods due to receiving the anti-barrier functionality later.