Are alien bettas shy?

I have a 75gal nano community with panda cories, rummynose tetras, golden white cloud minnows, neocaridina, and amano shrimp. It is heavily planted with massive crypts, java fern, moss, anubias, and buce.

Previously, I had a male plakat betta who was very social and active. He developed dropsy and declined quickly, so I euthanized him about 3mo ago.

A 6wks ago I got a new betta. She is a small alien plakat and was very social throughout quarantine in her 5gal. She ate great and then moved over to the 75gal. She has been in her new home for almost a month and I have only seen her twice.

Overall, I'm very dissapointed that she is so incredibly shy - I haven't seen her for 2wks and honeatly I wouldn't be suprised if she was dead. Are these types of bettas very shy?