Really interesting report - the tree line detail is key for me. That's classic liminal space behaviour, hovering at the boundary between open sky and dense cover. Seen similar myself out on the North Yorkshire moors, and the way you describe the movement (or lack of it) matches a handful of credible accounts I've been cross-referencing lately.
Few questions worth unpacking:
Duration - how long did it hold position before moving or disappearing?, Light quality - was it self-luminous or more of a reflective surface? Pulsing or steady?, Sound - any low-frequency hum? A lot of witnesses report a sub-bass sensation more than an audible noise, Your state - tired, stressed, had a drink? Not doubting you, just proper documentation requires ruling out perceptual factors
The hovering-over-tree-line configuration comes up repeatedly in Mothman and UAP literature. John Keel noted this pattern extensively - these things seem to prefer transitional zones. Woodland edges, coastlines, ridgelines.
If you can get back out there with a camera that handles low light reasonably well - a Sony A7S body is genuinely transformative for this kind of work - even a negative result is useful data.
What region are you in roughly? Happy to check if there's any geological or ley line activity in the area worth noting. Earth mysteries angle gets overlooked far too often in these discussions.