I lost about half of mine last year, probably for the reasons you mention here. I didn't really look into the matter as I'm too damn busy, but I have strongly suspected underhand shenanigans at Medium for several months now. For one thing, I've had an exponential rise in followers yet a significant drop in earnings (although this month, weirdly, it went up again). Something isn't quite right.

Still, most of my writing life is elsewhere, and I haven't time to investigate. Sorry to hear you and other commenters here have been ignored. All very irritating.