Territorial little guy?
This is something I've noticed as of today. What I'm seeing is that if I happen to be by Mojo's bubblenest when I go to see him, he swims over and kinda flares at me (not spreading fins out or anything, just puffing out his gills). And then it hit me, do bettas get kinda mad and or protective typically if they think you're near their bubblenest? It makes sense that he would but maybe he's not doing it for that reason (not sure why else though).
Rest in peace little Pizza. You were a true miracle who is dearly missed and will be forever loved by all who knew you. 2 years 10 months of love, life, and weirdness with the fish who just kept on living!