Encountering similar issues. I'm on a Lenovo LegionGo running Bazzite. I can activate Enpass and sign in to authorize the sync with my cloud storage but it just sits and spins after that, eventually timing out. I've tried using different browsers to authorize the sync but it doesn't matter.
May try and restore from a backup file, but if it's not going to successfully sync then I don't know how much good that will be as it's just going to end up being out of date as soon as I change or add anything elsewhere.