American here, but I've always known these to be distinctly different. ANSI art uses the full 256 character set (and mostly the extended, block-like characters), and 16 colors, whereas ascii art doesn't have the extended characters and colors. There was a thriving ANSI art scene in the 90s in the era of BBSs.
If you have not seen it, the definitive ansi (and ascii) art archive, 16colors, is great
https://16colo.rs/
If you have not seen it, the definitive ansi (and ascii) art archive, 16colors, is great https://16colo.rs/
Or try your hand with this online ansi art editor https://ansidraw.com/