As issue involves a 3rd party app, fix needs to be performed from the application side. It would be best if you let app developers know of this issue through their support channels.
YES I MOST CERTAINLY DO TOO. Glad to know I'm not the only one. Unfortunately I don't think either of the apps will be updated to be fully functional and compatible with the 12 UI 4.0 until the official release happens. But as the mod here said, I would advise letting Facebook and Instagram know you're having issues with the inability to open links on these apps. It'll help them just as much as participating in this beta and giving feedback does samsung.
