Hello and welcome, but sorry that you’re finding us under these circumstances.
What size is the Affinity Pond and what kind of fish are you keeping in it? Those are pretty small, if I’m remembering correctly.
So, what might be different now, at your current house, from what was at your old house? Different water source, pesticides, more or less sunlight, same volume of water….? Do you add any chemicals to the water (for any reason)?
Please tell us the exact numbers for your water tests. “All seems OK” doesn’t really give us any information. Also, test your source water. Oftentimes water from different sources can have different chemical properties.
Six weeks is about the time it takes for a pond to go through the nitrogen cycle……. Just an observation.