Nether of them are your friends. Fluxor seems a bit sketchy with their limited time cash grab of lifetime memberships, and GitHub history compression. Stoat is basically discord 8 years ago and is in the UK where age verification is law. It has time to change and their privacy policy doesn't look great (they also collect information from you).

Fluxor could be fine, I am just skeptical of it at the moment.

Stoat is better than discord, but not by much.