Apparently there's something called "anvil crawler" lightning that can work its way across a cloud.

https://en.wikipedia.org/wiki/Lightning

https://en.wikipedia.org/wiki/List_of_lightning_phenomena

Anvil crawler lightning, sometimes called spider lightning, is created when leaders propagate through horizontally-extensive charge regions in mature thunderstorms, usually the stratiform regions of mesoscale convective systems. These discharges usually begin as IC discharges originating within the convective region; the negative leader end then propagates well into the aforementioned charge regions in the stratiform area. If the leader becomes too long, it may separate into multiple bidirectional leaders. When this happens, the positive end of the separated leader may strike the ground as a positive CG flash or crawl on the underside of the cloud, creating a spectacular display of lightning crawling across the sky. Ground flashes produced in this manner tend to transfer high amounts of charge, and this can trigger upward lightning flashes and upper-atmospheric lightning.[1]

But in the video I see of it, while it's sustained by lightning standards, it all looks much shorter duration. This video is titled "Epic 3.72 second anvil crawler lightning", so over a minute seems unlikely.

Are you sure that it's not an aircraft, maybe illuminated in one way or another (e.g. a break in the clouds in the distance letting sun illuminate it directly, maybe?)

You know how lightning never strikes twice?

Well, that's a myth. It loves to strike the same place twice. Hot air left behind after a strike is a conductor for the next one.

Lightning is just electricity moving. Electricity is one of those natural forces that wants equilibrium. When it’s far enough out of equilibrium, it has pressure or power of whatever you think of it as. It wants equal, a zero difference, a flat and dead environment. And a difference in that between regions creates something actionable. Nature can do something with that.

Lighting is basically a spark we can see with the charge being equalized. It’s a trade nature is making to level things out.

If the exposure time on each of those stills is long enough, that could easily be ball lightning moving enough to cause a streak on each frame.

Ball lightning is rare, but has been observed to wander around slowly, occasionally with an explosive end. This doesn't go on long enough to see anything like that, though.

Either that or it's something else bright and point-like doing the same thing, caught in the wind maybe.

Aliens.

Hard to say without more info, and I don't know if there's more specific terminology, but yeah this isn't impossible. You need the right conditions, like enough electric potential in the right places, and the right conditions to make it "slow" (i.e. enough potential and a difficult-to-find path) but cloud-to-cloud and intra-cloud lightning is relatively common.

Lightning can jump from cloud to cloud. But that's a fucking alien.