Betta fast swimming and glass surfing?

[fishtime!]

Hi everyone, I was wondering if this is normal behavior or if its concerning. She doesn't do it all the time but sometimes instead of exploring her tank she swims really fast up and down the sides. I'm worried she's bored but I have so much stuff in there and I change out a tunnel or two every week it's hard to imagine that shes bored. I feed her three times a day, 4-6 frozen brine shrimp or fluval bug bite pellets. I do a two day fast on the weekends. (I know that's a lot of food but she hasn't gained any weight and she is swimming constantly, out of the two months I've had her I've never seen her sleep or rest so I figured it would be normal for her to eat more than other bettas I hear about. I feel like I'm probably over-worrying (because my last fish died of ammonia poisoning and started swimming really rapidly then had seizures and it was really horrible - I had no idea what I was doing!) but I just wanted to check and see if anybody had any thoughts. I'm linking a video of her swimming below

Tank Info:
Size: 20 G long
Water quality: 0 ammonia 0 nitrite 0-5 nitrate 7.6 pH
Decorations: Live plants, dragon rock and driftwood, floating tunnel, almond leaves
Water changes: 30% once a week + substrate vacuum
Tank occupants: female koi betta + some ramshorn and bladder snails