I'm new just as of now actually lol. I saw something similar with my betta. Only...he leaves normal tiny brown poops all over his anubias leaves..and then this morning he had a very small but longer bit of whitish poop hanging...3 min later it's gone after he swam around. He's completely normal, almost wags his fins when I came up to his tank and he swims with energy and curiosity all like normal. Up at the top, middle and bottom and poking into the hideouts and swimming through plants. I see nothing wrong with him so I have to wonder if he just ate some of that algae wafer or something else in there..I have live plants so I'm not sure. He seems fine though and not struggling to poop either. In fact right now, just minutes after my observation he is poking under the marimo moss balls in the search for the elusive amano shrimp I have in there. I'll keep watching him though, don't think he has any issues.