Hello there @AlePlay!
I'm sorry to hear that you're having issues with your desired mount cosmetics saving. I can confirm that @Ubi-Milky has forwarded your report regarding this to the dedicated teams and that they're looking into this further. I've also now let them know that this affects other mounts (such as the wolf), in case this helps with the ongoing investigation.
If the team require any additional information about your experience, we'll reach out within this thread.
The dedicated teams have also been notified about hidden gear reappearing after using the Power of the Raven, and they're looking into this further as well. Any future updates will be posted in the News & Announcements forum, so please keep an eye out for these.
@MssPrince - Just to clarify, are you encountering the issue wherein your chosen mount cosmetic will reset back to the default reindeer after fast-travelling/reloading saves? If so, would you be able to provide us with an additional video that showcases which cosmetic you've chosen to apply, as well as the reset occuring in-game?
I'd recommend uploading your video to a sharing platform, such as YouTube or Google Drive, as this will allow you to post a shareable link within this thread we can take a closer look at.
Would you also be able to provide us with some more details on how this issue has affected your keybindings?
Thanks!